[TxMt] save, activate, and deactivate commands

[Matthew Johnson]

> Actually Save is easy to do and I have been using it for a lot of  
> things like
>
> - Check Perl syntax on save
> - Automatically harvest/fill in markdown links on save
> - etc
>
> To set it up:
>
> - Define an empty Command, call it 'Save', set it to Save the  
> current file, and give it the Cmd-S shortcut (this is the fallback)
> - For languages where you want Save to do more do as above, but add  
> whatever command you desire and set the Scope Selector to the  
> desired language

Very cool trick!  It will let me do what I was thinking of when I  
originally came up with this idea.  Thank you very much! :)

Matthew