Added a namespace for filters and dried up the code.

Instead of repeating the networks over and over again, I think defining
them once would be best here. Now it's easier to add more in later on
(or remove some).

Also this helps to add filters on later ( I'll work on that very very
soon ).

This is not the best solution right now. Instead of using Variable
variables, we should use extract() on array in the template parts, but
that's something for another day.

I namespaced the filters because skype, facebook, etc. are pretty common names. I kept the old ones as well for now, for backwards compatibility. Though this should probably be removed very soon.

More to come tomorrow.