Integrating option parsing in TestCase for added convenience

To hook it up to individual test cases:
- define GetLongOptions() in your test case class to return something other than NULL (hopefully an array of options :-)
- implement ParseOption() to check for the short option char and do the right thing - return true at the end if you want more options to come your way or false if you don’t
- make sure that your Setup() call takes int& and char**& so that optind post-processing can happen - and call TestCase::Setup from your setup

llvm-svn: 178482