Change the default taskprocessor test so it will never hang forever.

Changes the ast_cond_wait() to an ast_cond_timedwait() so that
if there is an issue, we'll never wait forever for the task to
finish execution.



git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376411 65c4cc65-6c06-0410-ace0-fbb531ad65f3