Merge branch 'ms/git-svn-1.7'

Merge branch 'ms/git-svn-1.7'

A series by Michael Schwern via Eric to update git-svn to revamp the
way URLs are internally passed around, to make it work with SVN 1.7.

* ms/git-svn-1.7:
  git-svn: remove ad-hoc canonicalizations
  git-svn: canonicalize newly-minted URLs
  git-svn: introduce add_path_to_url function
  git-svn: canonicalize earlier
  git-svn: replace URL escapes with canonicalization
  git-svn: attempt to mimic SVN 1.7 URL canonicalization
  t9107: fix typo
  t9118: workaround inconsistency between SVN versions
  Git::SVN{,::Ra}: canonicalize earlier
  git-svn: path canonicalization uses SVN API
  Git::SVN::Utils: remove irrelevant comment
  git-svn: add join_paths() to safely concatenate paths
  git-svn: factor out _collapse_dotdot function
  git-svn: use SVN 1.7 to canonicalize when possible
  git-svn: move canonicalization to Git::SVN::Utils
  use Git::SVN{,::RA}->url accessor globally
  use Git::SVN->path accessor globally
  Git::SVN::Ra: use accessor for URLs
  Git::SVN: use accessor for URLs internally
  Git::SVN: use accessors internally for path