Update travis to use a newer SDCC

Due to SDCC bug #1986, we were previously stuck
with SDCC revision #7100. The bug was fixed with
rev #8719. Thus, we can now use newer versions

More info: http://sourceforge.net/p/sdcc/bugs/1986/
Merge pull request #319 from g-oikonomou/travis-new-sdcc

Update travis to use a newer SDCC
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
Add CC2538 travis compile tests
Merge pull request #320 from g-oikonomou/travis-cc2538

Add CC2538 travis compile tests
Merge pull request #306 from adamdunkels/push/travis-mspgcc-4-7-0

Update travis to use mspgcc 4.7.0
Prevent erroneous index creation for non-numerical attributes.
Merge pull request #321 from nvt/antelope-domain-check

Prevent erroneous index creation for non-numerical attributes in Antelope.
Add support for verbosity control
Adjust a config define to its new name
Update readme references and tool download URLs
Read IEEE address from InfoPage by default
gitignore CC2538dk firmwares
Merge pull request #326 from g-oikonomou/cc2538-contikimac

Adjust a config define to its new name