[StGit] Mostly-Emacs-mode merge request

Catalin, can you please merge the following series from the git://github.com/gustavh/stgit.git "proposed" branch.

Most (all but two) of the patches are incremental improvements to the Emacs mode.

4d2357d stgit.el: Make stgit-commit commit at most as many patches as are available 55deb92 stgit.el: Set file names when calling smerge-ediff fc6a66e stgit.el: Handle file names that must be quoted 5b2c8ad stgit.el: Stop stgit-rename from causing error on no change 7347eb8 stgit.el: Use truenames when finding an already-existing stgit buffer 9d9e179 stgit.el: Fix bug when displaying non-stgit branches 059f8e0 stgit.el: Catch errors in a better way in stgit-init ffeee13 stgit.el: Make sure to set major mode in stgit-capture-output aceb7d0 stgit.el: Change stgit-capture-output to return what its body returned f46c584 stgit.el: Make \C-o create new patch at point 0e495dd stgit.el: Allow opening specific revisions of files f19eb1f stgit.el: Fix problems with revert of unmerged files 0cc7509 stgit.el: Allow "U" to delete unknow/ignored files and directories 6ed6218 stgit.el: Add and use stgit-assert-no-unmerged-changes f282cf8 stgit.el: Add and use stgit-save-excursion 64b814f stgit.el: Make "i" set mark correctly when working on the entire patch ab228bc stgit.el: Change return value of stgit-goto-patch 970a74e stgit.el: Refactor: rewrite stgit-define-toggle-view c6a5c10 stgit.el: Show human-friendly message when {expand,collaps}ing patches 2147794 stgit.el: Show human-friendly message when pressing = 2c1769c stgit.el: Add and use stgit-show-task-message to show messages 7246e70 stgit.el: Delay buffer reloads when setting customization variables 7e1b5aa stgit.el: Make stgit-previous-patch move to the current patch if on a patched file. 6805d5c stgit.el: Unexpand all (normal) patches when switching branches 724dba9 stgit.el: Do not tab complete on current branch for stgit-branch f8c77f2 stgit.el: Make stgit-branch ask whether to merge uncommitted changes 5cabf6c branch: Add --merge flag when switching branches 9a60c57 ignore error return from git show-ref when reading ref cache 43f11d8 stgit.el: Make "\C-u !" run git even when no patches are selected

Thanks,
 Gustav

PS. The documentation in http://www.procode.org/stgit/doc/ needs to be updated to 0.16.