Switch to mspgcc 4.7.0
Updated mspsim.jar

The Contiki source code holds a binary version of mspsim.jar until
we get a proper git submodule set up. This particular version of mspsim.jar
is built from Thingsquare's mspsim fork.
Added mspgcc 4.7.x flags
Filter out symbols defined by the C implementation
Parse rodata too
Allow the exit code from a failed test script to propagate to the Java
process, which makes it possible to track failing tests in makefiles and
via scripts.
Turn off the LCD by default as it is somewhat flaky
Merge pull request #306 from adamdunkels/push/travis-mspgcc-4-7-0

Update travis to use mspgcc 4.7.0