contact export, include group option lists hidden groups

in the contact export dialog we have the option of including contacts in a static group. that select list includes hidden groups, and shouldn't.

the problem is that our pseudoconstant function "staticGroups" does not exclude hidden groups (and doesn't provide a parameter to)

the attached patch adds that parameter and sets it as the default. so unless explicitly requested, that function now returns all static groups less any hidden groups.

i grep'd the code and there are a number of other places that pseudoconstant is called. but in a quick review of them, I think we want hidden groups excluded for all of them. however, core team will want to review and confirm.