ENH: add convenience function to convert Windows command line args into Unix argc/argv. Pulled and cleaned from PV/VV/VJ init code

BUG: struct timeval uses unsigned types on at least one platform (QNX).  Alot of the time logic assumes a signed type.  Switch to using a signed representation that is converted to the native representation only for system calls.

ENH: Disabling test 6 on QNX until process killing can be resolved.  It will just fail always for now.

BUG: Extending timeout of test 6 from 0.1 seconds to 3 seconds.  This should avoid missed signals and intermittent failures.

BUG: Drastically extending test5's timeouts to get it to pass when running on a heavily-loaded machine.