Reorganize to properly build for lithe support

Valid for both ros and linux
Build with lithe support

Still not spawning separate lithe schedulers for each parallel function
call, but the main infrastructure is in place with all lithe contexts
spawned in the base lithe scheduler.

Next need to modify tests to make sure they use lithe properly.
Reorganize so that libgomp_lithe_sched can be statically sized
Only build lithe files if --enable-lithe configured
Force 'make check' to use the newly created libgomp

As opposed to the one installed on the system already
Bug in naming of PARLIB_NO_UTHREAD_TLS, now fixed
First real "sort of" working version with lithe

Includes a self maintained pool of zombie contexts to optimize the
lithe_context_create() path.