connecting/disconnecting from activities

[Marco Martin]

Hi all,

when someone wants to connect some resource to an activity, from the slc 
applet (or a search result from the search menu in the panel) there is the sub 
menu "connect"

now, we have two possible approaches there:
until last commit: click on "activity" the menu slides and shows all the 
activities with a checkmark on what are the connected ones
	pros: very fast to connect something to an arbitrary subset of activity
	cons: more complex, what happens if the activity list will be huuuge?

at last commit: just "connect/disconnect from activity"
	pros: very simple and intuitive
	cons: longer interaction if i want to connect to something else, switch to 
activity, *then* connect

I'm bringing this up since there was a little misunderstanding, i.e. i tought 
everybody agreed on latter while isn't actually the case ;)

so, both approaches have advantages and disadvantages, depends on what of 
those two things should be favored.

Cheers,
Marco Martin