BP_Component improvements:

* Improve accuracy of phpdoc
* Correct default parameter values
* PHP5'ize (no scope changes)
* No functional changes, but motivated by changes that will be part of #4954

git-svn-id: https://buddypress.svn.wordpress.org/trunk@6953 cdf35c40-ae34-48e0-9cc9-0c9da1808c22
Introduce bp_add_rewrite_tags() and connect bp_generate_rewrite_rules() sub-action. See #4954.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@6954 cdf35c40-ae34-48e0-9cc9-0c9da1808c22