Fix arbitrary path limits and improved error handling (exit
even if not built with asserts).
sort and remove some includes
Refactored part of KleeHandler construction so that
- A fixed size buffer is no longer used for output Directory path
  (would of failed for large paths).
- KLEE warns about the presence of klee-out-* files that aren't
  directories.
- We don't get stuck in an infinite loop if there aren't available
  directories.
Exit if using --libc=uclibc and KLEE was not configured with uclibc
or if the configured path does not exist.

Previously if KLEE was configured and compiled without uclibc linking
would still succeed because KLEE_UCLIBC was blank so LLVM was
effectively asked to link with "/lib/libc.a" i.e. the system's native
C library!
Merge pull request #63 from delcypher/nouclibc

Exit if using --libc=uclibc and KLEE was not configured with uclibc