Fix testcase FD_Fail2.c

Major issue was that puts was used for the succeed printf calls.
With newer gcc/clang versions, printf is always used.

The former took different code paths leading to much more possibilities
to trigger failed writes and therefore generating more test cases.

This patch avoids the generation of puts.
And checks for the 4 possible generated test cases for 2 possible errors.
Use not test instead of non-existing FAIL.
Merge pull request #155 from MartinNowack/fix_fd_fail2

Fix testcase FD_Fail2.c
Use klee-libc for this test, as it runs when configured w/o uclibc.

 - If this is a problem for some reason, lets either fix the problem or move it
   into Runtime tests.
[Core] Remove support for "--use-asm-addresses".

 - I suspect no one is using this feature, and I'm not sure it is well conceived
   either. Ripping it out for now in lieu of bothering to maintain it.
[tests] Enable running tests in parallel.

 - This works fine for me on OS X now, and has been reported to work on Linux as
   well. Enabling across the board although presumably Travis will still only
   run single-threaded.

 - Fixes #147.
[Module] Try harder to associate each instruction with source level debug info.

 - This makes KCachegrind output look nicer, as otherwise it assumes
   instructions without debug info were inlined and shows some message to that
   effect.

 - This does however we might be lying a bit about the source line that an
   instruction came from.

 - This also adds a test case for our istats output, yay!
[Core] Fix a bug in how source file names were written in .istats files.

 - KCachegrind appears to expect the first function name to be preceeded by the
   name of the file it appears in. Otherwise, it will end up creating two
   different records for the function, one of which has no file name and won't
   have any statistics.
Fix when we decide to "not exit on command error". We were doing this
too late so if the unittests failed the lit tests would not run.
Clean up travis build scripts a little.
Capture STP build output to file and only show its contents if there
is a build failure. This is so the output shown in the TravisCI
web interface is kept small.