Fix misuse of python subprocess module (caused "leaking" processes and garbling the terminal)
- fixed cleanup of Popen objects by pushing spawn logic into test Base and out of test cases
- connect subprocess stdin to PIPE (rather than the parent's STDIN) to fix silent terminal issue

Tested on Linux and Mac OS X



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@175301 91177308-0d34-0410-b5e6-96231b3b80d8
More test case cleanup (Linux and Mac):
- remove expectedFailure decorator from resolved rdar 12566646 and 10887661
- remove expectedFailure from TestBitfields testcase not actually affected by bug
- skip the (non-deterministic) TestStopHookMechanism.py to avoid a noisy suite on Linux



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@175307 91177308-0d34-0410-b5e6-96231b3b80d8
Improve test harness for the buildbots
- Add a "parsable" mode to dotest.py that outputs test results in exactly the same format as clang's lit tests
- Improve dosep script to output list of failing tests (output should look like clang test failure summaries)
- Cleanup lldb/test/Makefile to remove needless parameters and environment variables
- Switch makefile tests to use parsable-mode output; should make the buildbot results parsable
- Switch makefile tests to use dosep to log catch crashing tests (instead of halting the test suite)



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@175309 91177308-0d34-0410-b5e6-96231b3b80d8