Missing create_ce_mode calls when creating cache entries
Add support for remote.<name>.gitpath

gitpath specifies the path on the git side that should correspond to the
svn path. Fetches create entries relative to this directory for the git
commit, and pushes to svn restrict to this path. The tree in the svn
commits are unaffected.
uninitialized variable
The push code was reliant on there being a valid credential but didn't actually make sure to grab one
add comment for twigs in the push rules and log xml parse error data
When pushing a merge update the svn:mergeinfo with the full branch range rather then the just relevant commits

SVN treats revisions that only affect other branches as affecting this
branch from a merge standpoint. So instead of updating the mergeinfo
with /Branch/MyBranch:22,24,26, because 23 and 25 were commits on trunk,
we should instead update it with /Branch/MyBranch:22-26. Otherwise the
svn reintegrate merge doesn't work and it leaves the mergeinfo in a
cleaner state.