[Dextrose] Check for required activity deps before installing

[Bernie Innocenti]

On Wed, 2011-01-12 at 14:32 +0000, Aleksey Lim wrote: 
> It is a mimic of sweets' requires tag that will be used only for sugar
> dependency. Full functional dependency tracking will come with sweets support
> implementation in the shell.

/me likes this

Let's merge it into dextrose2 now to allow early testing by activity
authors.


> Dependency check will happen only for installation. Since in most cases
> it should be enough and launching code is scattered among the shell code
> (porting the 0.90 patch that fixes it, might be invasive for dx-2).

I think it's good enough for now. It's already a huge improvement over
the current situation.


By the way, where is the activity.info documentation in our wiki? After
searching a lot, I found this page:

http://wiki.sugarlabs.org/go/Development_Team/Almanac/Activity_Bundles

Shouldn't we move it under the Activity_Team hierarchy?

-- 
   // Bernie Innocenti - http://codewiz.org/
 \X/  Sugar Labs       - http://sugarlabs.org/