Added priority feature

I've adde a priority feature so you can type c+tab h+tab l+tab for critical high low priority. I've choosed this priority because "critical" has more chars than "high" and "high" has more chars than "low" so you have the evidence of a bigger color label for high priority task.

I've also modified al themes to have the coloring in all cases
It's my first github contribution... I'll fix it.
Il 12/nov/2014 11:00 "Vova Kolobok" <notifications@github.com> ha scritto:

> In PlainTasks.tmLanguage:
>
> > @@ -16,7 +16,7 @@
> >  	<array>
> >  		<dict>
> >  			<key>match</key>
> > -			<string>^\s*(\w+.+:\s*?(\@[^\s]+(\(.*?\))?\s*?)*$)</string>
> > +			<string>^\s*(\w+.+:\s*(\@[^\s]+(\(.*?\))?\s*)*$\n?)</string>
>
> If there are no reason, please fix it and add note in readme and tutorial,
> then I’ll merge.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/aziz/PlainTasks/pull/188/files#r20210136>.
>