Add support for -X to git SCMClient

Review Request #6339 — Created Sept. 19, 2014 and submitted — Latest diff uploaded

Information

RBTools
master
191bc37...

Reviewers

Git (and the git-svn and git-p4 backends) now support the -X/--exclude
commandline option and the EXCLUDE_PATTERNS .reviewboardrc option.

Add unit tests for excluding files from Git diffs.

Rename exclude_files/EXCLUDE_FILES to exclude_patterns/EXCLUDE_PATTERNS
to reflect the actual behaviour of -X.

Unit tests pass.

Generated diffs with excluded files via rbt diff with git, git-svn,
and git-p4.