[development] module names and namespaces

[Daniel F. Kudwien]

> If you want a concrete example, both fb.module and 
> fb_social.module define variables starting with "fb_"

The fb_social module is therefore violating namespace rules.  It may only use
names within the "fb_social" namespace, but not "fb".

There are more complex namespace problems with module names and hooks, but this
case sounds like the easy case.

sun