BuddyPress should use mapped meta caps

[johnjamesjacoby]

Currently BuddyPress relies on a few stub functions and is_super_admin() to handle the things a user is capable of doing. This is rather lame, and provides no ability to align the moderation needs of your site with the users that are tasked with moderator level responsibility.

In r5304, r5305, and r5309, some API's were ported from bbPress 2.0 to get this started. Please use this ticket for discussion, patches, and commits towards BuddyPress roles and capabilities for the 1.6 dev cycle.

See #3739 for original ticket.

See also #2348, which I'm closing in favor of this ticket since it's tied to things that have already been put into the BP trunk.

(In [5329]) Find/replace on is_super_admin() to use bp_current_user_can( 'bp_moderate' ). See #3740.

(In [5330]) Audit is_super_admin and is_site_admin usage. See #3740.

(In [5332]) Add is_super_admin() check to beginning of bp_current_user_can() while in development to keep trunk working normally. See #3740.

(In [5333]) Make all core functions available on installation. Needed for adding roles and caps. See #3740.

I think that we have done as much with this during the 1.6 cycle as we are going to. Let's talk about it early in the 1.7 cycle to see how we're going to take it further.

(In [5656]) Reconfigures require() order for loading process during installation and upgrade.
Corrects outdated function calls and path names in installation wizard.
See #3740.
Fixes #3875. Fixes #3802. See #3865.

I'm against doing a massive refactor of our permissions structure just to meet the requirements of this ticket, especially during what is already turning out to be a crowded milestone. But I do think that we should leave this ticket open, and refactor individual instances as we see fit (and as it will actually be beneficial).