Not exporting branch copies is a difference
Rename main group of tests under RepoTests class
Rename Repo() to Exporter() and separate export() method
Collect mergeinfo
Always keep track of the base for each exported revision

Also, save the base Git revision rather than looking it up again.
Separate out get_location_segments() function
Ancestors class to collect natural and complete merge history
Work around issue with cancelling a Subversion Serf operation
Merge branch 'master' into HEAD

Conflicts:
	test_svn_fex.py