J2objcPodTask fixes and error message improvements

- Fixed depProj => project which didn’t run before
- Fixed j2objcHome which didn’t run before
- Hard code podVersion as '1.0'

Error Message Improvements:
- Missing podfile
- Missing pod command

j2objc.gradle

@@ -1078,13 +1078,16 @@ class J2objcPodTask extends DefaultTask {
     @TaskAction
     def pod(IncrementalTaskInputs inputs) {
 
-        if (project.j2objcConfig.xcodeProjectDir == null) {
-            def message = "You must specify the xcodeProjectDir"
-            throw new InvalidUserDataException(message)
-        }
+        if (project.j2objcConfig.xcodeProjectDir == null ||
+            project.j2objcConfig.xcodeTarget == null) {
 
-        if (project.j2objcConfig.xcodeTarget == null) {
-            def message = "You must specify the xcodeTarget"
+            def message =
+                    "Xcode settings needs to be configured in the build.gradle file:\n" +
+                    "\n" +
+                    "j2objcConfig {\n" +
+                    "    xcodeProjectDir \"\${projectDir}/../Xcode\"\n" +
+                    "    xcodeTarget \"<TARGET_NAME>\"\n" +
+                    "}\n"
             throw new InvalidUserDataException(message)
         }
 
@@ -1093,41 +1096,47 @@ class J2objcPodTask extends DefaultTask {
         def lineSeparator = System.getProperty("line.separator")
 
         // Resource Folder is copied to buildDir where it's accessed by the pod later
+        def j2objcHome = J2objcUtils.j2objcHome(getProject())
         String j2objcResourceDirName = "j2objcResources"
         String j2objcResourceDirPath = "${project.buildDir}/${j2objcResourceDirName}"
         project.delete j2objcResourceDirPath
         project.copy {
-            from J2objcUtils.srcDirs(depProj, 'main', 'resources')
+            from J2objcUtils.srcDirs(project, 'main', 'resources')
             into j2objcResourceDirPath
         }
 
         // create the podspec
         def podName = project.name
         def podspecName = podName + ".podspec"
-        def podVersion = project.version
         File podspecFile = new File(project.buildDir, podspecName)
         podspecFile.write("")
         // TODO s.libraries: this will not function for anyone who has their own list of linked libraries in the compileFlags
         podspecFile.append(
             "Pod::Spec.new do |s|" + lineSeparator + 
             "s.name = '${podName}'" + lineSeparator + 
-            "s.version = '${podVersion}'" + lineSeparator + 
+            "s.version = '1.0'" + lineSeparator +
             "s.summary = 'Generated by the j2objc.gradle plugin.'" + lineSeparator + 
             "s.source_files = 'j2objc/**/*.{h,m}'" + lineSeparator + 
             "s.public_header_files = 'j2objc/**/*.h'" + lineSeparator + 
             "s.resources = '${j2objcResourceDirName}/**/*'" + lineSeparator + 
             "s.requires_arc = true" + lineSeparator + 
             "s.libraries = 'ObjC', 'guava', 'javax_inject', 'jre_emul', 'jsr305', 'z', 'icucore'" + lineSeparator + 
-            "s.xcconfig = { 'HEADER_SEARCH_PATHS' => '${J2objcUtils.j2objcHome(project)}/include', 'LIBRARY_SEARCH_PATHS' => '${j2objcHome}/lib' }" + lineSeparator + 
+            "s.xcconfig = { 'HEADER_SEARCH_PATHS' => '${j2objcHome}/include', 'LIBRARY_SEARCH_PATHS' => '${j2objcHome}/lib' }" + lineSeparator +
             "end")
 
         // link the podspec in pod file
         File podFile = new File(xcodeProjectDir, "Podfile")
         if (!podFile.exists()) {
-            def message = "No podfile exists at path ${xcodeProjectDir} execute 'pod init' first in your project directory"
+            // TODO: offer to run the setup commands
+            def message =
+                    "No podfile exists in the directory: ${xcodeProjectDir}\n" +
+                    "Within that directory, create the podfile with this command:\n" +
+                    "    pod init\n" +
+                    "\n" +
+                    "If the pod command isn't found, then install CocoaPods:\n" +
+                    "    sudo gem install cocoapods"
             throw new InvalidUserDataException(message)
-        }
-        else {
+        } else {
             logger.debug "Pod exists at path: ${xcodeProjectDir}"
             // check if this podspec has been included before
             def result = J2objcUtils.checkPodDefExistence(podFile, xcodeTarget, podName) 
@@ -1155,17 +1164,25 @@ class J2objcPodTask extends DefaultTask {
                     errorOutput output
                 }   
             } catch (Exception exception) {
-                logger.debug output.toString()
-                logger.error 'Error during pod install:'
+                logger.error output.toString()
 
-                // unrecognized errors are rethrown:    
                 if (exception.getMessage().find("A problem occurred starting process 'command 'pod install''")) {
-                    // TODO: fix this installation description
                     def message =
-                        "To install pod: sudo gem install cocoapods \n" +
-                        "See: https://cocoapods.org/"
+                            "Fix this by installing CocoaPods:\n" +
+                            "    sudo gem install cocoapods \n" +
+                            "\n" +
+                            "See: https://cocoapods.org/"
                     throw new InvalidUserDataException(message)
                 }
+                if (output.toString().find("ArgumentError - Malformed version number string unspecified")) {
+                    // TODO: Add instructions on how to configure project.version
+                    def message =
+                            "Fix this by specifying a project version:\n" +
+                            "<ADD INSTRUCTIONS>"
+                    throw new InvalidUserDataException(message)
+                }
+
+                // unrecognized errors are rethrown:
                 throw exception
             }
             logger.debug 'Pod install output:'