Remove the now-empty `includes/admin/images` directory. Props netweb. See #2542.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5307 9866e705-20ec-0310-96e7-cbb4277adcfb
Don't copy Sass files (or any other excluded files) into `/build` directory. Props netweb. See #2542.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5308 9866e705-20ec-0310-96e7-cbb4277adcfb
Introduce topic & reply counts for users:

* New functions for updating user options.
* New action hooks for bumping existing counts on CRUD actions.
* Uses existing `_raw` functions when no counts are previously found to incrementally update missing meta values.
* Tool for updating topic & reply counts already exists.
* Props netweb, MZAWeb, anointed.
* Fixes #1694.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5309 9866e705-20ec-0310-96e7-cbb4277adcfb
Allow topic-tag descriptions to be edited theme-side. Props netweb. Fixes #1613.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5310 9866e705-20ec-0310-96e7-cbb4277adcfb
Use correct uppercase type hinting for forum meta queries.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5311 9866e705-20ec-0310-96e7-cbb4277adcfb
Use 'array_diff()` rather than `array_intersect()` in `bbp_pre_get_posts_normalize_forum_visibility()` to allow custom `post_type` queries (that still include forums/topics/replies) to pass through without hidden/private forum `meta_data` assistance. Fixes #2471.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5312 9866e705-20ec-0310-96e7-cbb4277adcfb
Allow closed topics to be split and merged into. Props netweb. Fixes #1714.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5313 9866e705-20ec-0310-96e7-cbb4277adcfb
Add contextual help for admin Tools. Props netweb. Fixes #1920.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5314 9866e705-20ec-0310-96e7-cbb4277adcfb