Fix basename filter in `bbPress:setup_globals()`. Props DJPaul.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5316 9866e705-20ec-0310-96e7-cbb4277adcfb
Don't allow `build` or `src` in `basename` in `bbPress:setup_globals()`. Fixes problems with activation hooks. Fixes #2559. Props DJPaul.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5317 9866e705-20ec-0310-96e7-cbb4277adcfb
Add screenshots to `readme.txt`. Props netweb. See #2555.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5318 9866e705-20ec-0310-96e7-cbb4277adcfb
Fix duplicate action name in form-forum.php. Props netweb. Fixes #2560


git-svn-id: https://bbpress.svn.wordpress.org/trunk@5319 9866e705-20ec-0310-96e7-cbb4277adcfb