0.5 - one mount to bind them all edition

Changes in this release include:

• Added amd64 Arch package.
• Added clarifying tarball instructions to readme.
• Conformed service enablers to standard practice.
• Added existence condition check to pstorefs/securityfs mounters.
• Converted X11 symlink to bind mount.
• Fixed assorted errors in the README.md. (Thanks to @mangkoran for proofreading.)