add two scenarios, one with a single, global database and one with
multiple project databases and usher as proxy; add an option for additional
command line options for the mtn process; remove the protocol type
configuration option - we're handling this implicit with the new
mtn_remote_url configuration
* Monotone.php: add the IDF user for ssh:// URIs; add support for remote_stdio
and rework the command line stitching
* IDF_Project: optionally give getSourceAccessUrl() a commit argument, so a particular VCS module can determine a subset of revisions to pull for the specific revision which is browsed
* IDF_Scm_*: add the argument null'd for all VCS; implement a branch lookup for monotone
* tree.html: display the correct branch to clone under each revision tree
* Monotone.php (IDF_Scm_Monotone_Stdio): add support for multiple, equally named options
* Source.php, commit.html: split-off the global commit template (which had some separate code already for SVN) and adapt the left blocks for mtn to shorten branch and tag names just like we do everywhere else
* _getCerts(): implement a cert cache and make multiple cert values easily available
* getCommit(), getCommitLarge(), getFile(), getPathInfo(), testHash(): implement
* getTags(): save the first found revision id for a tag as key in the associative array to make tags actually browsable
