ENH: Add copyright, cmConfigure.h is now touched only when it is modified, remove some spaces from output, add procedure that copies file and replaces atstring with another string

Removed Exception_Abort because there is no windows version.  Also made ExitValue consistent with windows when a signal kills the process.

ENH: Added documentation to interface.  Finished process exit code interpretation implementation prototype.

BUG: Fixed check for existence of CMakeLists.txt file in top-level source directory before first configure.

ERR: Using GetCurrentProcessId instead of _getpid so we don't need to include the system process.h header.  Also creating pipe threads with 1K stacks to save memory.