Created a new executive job that waits for threads to finish and readies them
for their next frame of execution. Created a new job class system_thread_sync
after the top of frame jobs and before the input processor is run to sync the
threads. Along the way cleaned up instrumentation jobs on the threads to fix#290.
Created a thread trigger container class to hold all of the various thread triggering
mechanisms. I wanted to avoid allocating/freeing trigger mechanisms. I added
an eventfd and futex trigger types. Updated SIM_threads_simple test sim to use
show how to set the thread trigger type.
refs #148
Conflicts:
trick_source/sim_services/Executive/include/Threads.hh
trick_source/sim_services/Executive/src/Executive_set_thread_rt_semaphore.cpp
trick_source/sim_services/Executive/src/Threads.cpp
Changed all header file once include variables to follow the same naming
convention and not start with any underscores. Also deleted old
incorrect copyright notices. Also removed $Id: tags from all files.
Fixes#14. Fixes#22.
