Update mspsim submodule

Commits:
c82dc9e Merge pull request contiki-ng#60 from nfi/dos-to-unix
60eb9d5 Convert DOS formatted files to Unix for consistent line endings.
9a752cd Merge pull request contiki-ng#59 from nfi/minor-code-cleanup
3d51407 Merge pull request contiki-ng#57 from nfi/tests
cf48bd1 Merge pull request contiki-ng#58 from nfi/flash-fix
c1762b3 Updated README to use 'ant' instead of 'make'
15d8882 Use StringBuilder instead of StringBuffer
8951db5 Minor code cleanup
b7b1a21 Corrected Javadoc argument names
5c9b6f7 Remove deprecated and unused methods
9400ad4 Make some inner classes static
a840a8a Corrected flash emergency exit check
27c09d7 Corrected bit shift in CC2420 log output
b1daf72 Removed Makefile - use ant to build instead
e243d61 Added targets for missing node types + target to run tests
b082842 Add pre-built firmwares for tests
e8b7814 Fail with error when test fails
61b84a0 Updated tests to build with msp430-gcc 4.7.x