submodule branch tracking

Git 1.8.2 (I think) added the the ability to track specific branches in submodules, but Sourcetree only seems to partly support it.

Specifically, when you do "Add Submodule..." I see that the command is called with the "-b" option and the branch specified (if you use the advanced settings). However, when you "Pull" from the parent repository it always executes "git submodule update --recursive --init". This will always put the submodule back to the commit stored with the parent repository. If the "--remote" argument is also supplied, it will first pull the given branch to the submodule.

At some level this is as simple as adding "--remote" to the submodule update command, although I'm sure everyone would like the ability to set this on a per-submodule basis (so some submodules can be semi-static, referring to a specific commit unless specifically changed).