Add -e/--exclude to git-clean.

Changes:
- Use -e multiple times instead of using a separator

I'm starting a new thread since the code change is rather major. I've incorporated Julio's changes, touched up on them a bit, and updated the test suite so that it uses multiple instances of -e rather than using a separator in them.

Thanks to Julio and all that helped.

Jared Hance (2):
Add -e/--exclude to git-clean.
Add test for git clean -e.

 Documentation/git-clean.txt |    8 +++++++-
 builtin/clean.c             |   17 ++++++++++++++++-
 t/t7300-clean.sh            |   16 ++++++++++++++++
 3 files changed, 39 insertions(+), 2 deletions(-)