Second pass at huge component refactor.

Move component files out of root directory and append '-loader' to the file names. Split those files up into smaller pieces.

Abstract 'settings' component out of 'core' and into its own component for future extension, including new template files in bp-default.

Append '-sa' to bbPress bridge file for 'Stand Alone' compatibility, to make room for bbPress plugin compatibility layer.

Various bug fixes through-out all components. Various code clean-up and documentation through-out all components.

Still more refactoring to do.