git-svn: reuse open SVN::Ra connections by URL
git-svn: reuse open SVN::Ra connections by URL

Note: this can cause problems with Perl's reference counting GC,
so I'm disabling Git::SVN::Ra::DESTROY.  If we notice more
problems down the line, we can disable this enhancement.

Signed-off-by: Eric Wong <8c2951295f8292b0c03727bc4652981172298eae@yhbt.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git