More robust template redirect needed

[johnjamesjacoby]

bbPress uses WordPress's capabilities API to ensure that only authorized users are able to perform certain tasks. What it doesn't have currently is a way to consistently redirect unauthorized users away from pages they might not belong at.

Right now some code is in a pre_get_posts filter, while some other are littered around their specific template loaders. This makes it difficult to see what's redirecting when, and why.

[johnjamesjacoby]

(In [3605]) Introduce bbp_template_redirect() and use for checking various edit screens:

• Introduce bbp_check_topic_edit() to check for topic edit
• Introduce bbp_check_reply_edit() to check for reply edit
• Introduce bbp_check_topic_tag_edit() to check for topic tag edit
• Introduce bbp_check_user_edit() to check for user edit
• Remove these checks from bbp_pre_get_posts() and only use it to setup query vars
• See #1684
• For 2.0 branch

[johnjamesjacoby]

(In [3607]) Introduce bbp_template_redirect() and use for checking various edit screens:

• Introduce bbp_check_forum_edit() to check for forum edit
• Introduce bbp_check_topic_edit() to check for topic edit
• Introduce bbp_check_reply_edit() to check for reply edit
• Introduce bbp_check_topic_tag_edit() to check for topic tag edit
• Introduce bbp_check_user_edit() to check for user edit
• Remove these checks from bbp_pre_get_posts() and only use it to setup query vars
• Fixes #1684, r3605
• For 2.1 (plugin) branch