[SVN] New Subversion stuff breaks my mnemonics

[Allan Odgaard]

The subversion menu has partially been crafted for easy keyboard  
usage, so that one could in the past do ⌃⇧A + C for Commit,  
⌃⇧A + S for Status, ⌃⇧A + D for Diff (and maybe arrow down to  
select the type of diff) etc.

Now with the recent Check Out and Show Available Revisions for  
Merging one of the two most used mnemonics are broken.

It would probably be confusing to limit ⌃⇧A to just a subset of  
the Subversion actions, but I would like to find a fix for this.