thread_manager fix/refactor, key handling fix, whitespace, race conditions

everywhere:
- fixing whitespace to use tabs again (editor fun)
- changed names of routines in thread_manager to be consistent
- added wrapper to pthread_create to unify thread tracking, everyone
uses new method to create threads
- removed more fprintfs and changed to verb

crypto.cpp:
- hardcoded key length (for now)

debug_output.cpp:
- set logging back to append to existing file as opposed to creating new

parcel.cpp/h:
- checking pipes on open, seeing if we have crap in them
- close handle opened with popen
- added a few control types (not using now)

postmaster.cpp/h:
- added variable for check to wait to send files in global_data_t

receiver.cpp:
- added routine to send control message to say receiver is ready (not
currently used)
- added routine to validate header (not currently used)

sender.cpp:
- added more cases to handling control messages

thread_manager.cpp/h:
- fixed bug in check for exit that could have been set off by improperly
closed threads
- changed naming convention of functions to be consistent with rest of
files
- encapsulated pthread_create within create_thread to centralize
handling

testParcel.py:
- round trip count is now 1 based
- added sleep between passes
- use wait to kill any threads after, after giving them time to exit