Update .gitignore from https://github.com/github/gitignore keeping Vim and emacs cruft
Use tester.py's built-in coverage and coverage.py's built-in cleanup
Read existing data coverage on measurement start, save on stop. Only measure PIL code.
pep8 Tests/tester.py
Start coverage measurement earlier so tests are properly covered
Merge pull request #607 from hugovk/master

Fix test coverage