Allow passing arbitrary command line flags to klee and kleaver
when running llvm-lit. This is done by doing something like

$ cd test/
$ llvm-lit --param klee_opts=--xxx --param kleaver_opts=--yyy .

This would pass "--xxx" as an extra option to KLEE when running
tests and would pass "--yyy" as an extra option to kleaver when
running tests.

This feature has been added to make it easy to pass different flags to
KLEE or Kleaver without needing to modify tests or recompile KLEE with
different defaults (yuck!).
Fix Runtime/POSIX/Isatty.c test under LLVM3.3. The program makes
a call fprintf(stderr,...). llvm-gcc transforms this to a call to
fwrite() however clang does not so klee-uclibc's fprintf will be
called instead and if klee-uclibc is compiled with KLEE_SYM_PRINTF
then output will always go stdout if the FILE is stdout or stderr.

The end result of this is that when we build with Clang under LLVM3.3
is that the fprintf(stderr,...) print outs go to standard output instead
and so the test would fail because it expects the fprintf(stderr,...)
to be on stderr.

This test sort of fixes this by having the test check stdout for
the fprintf(stderr,...) statements too.
Merge pull request #101 from delcypher/fix_isatty_llvm33

Fix Runtime/POSIX/Isatty.c test under LLVM3.3.
Explicitly propagate CPLUS_INCLUDE_PATH and C_INCLUDE_PATH environment
variables in llvm-lit. This should hopefully fix the build bot.

The propagation of environmental variables was also slightly refactored.
Merge pull request #100 from delcypher/pass-param-llvm-lit

Allow passing arbitrary command line flags to klee and kleaver when running llvm-lit