Bump tested-up-to version to 4.0. (trunk)

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5460 9866e705-20ec-0310-96e7-cbb4277adcfb
Use the correct `EMPTY_TRASH_DAYS` const.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5462 9866e705-20ec-0310-96e7-cbb4277adcfb
Bump NPM package versions in `package.json`
* "grunt-sass": "~0.14.0 -> "~0.14.1"
* "grunt-wp-i18n": "~0.4.7 -> "~0.4.8"
* Requires `npm install` to update packages and dependencies





git-svn-id: https://bbpress.svn.wordpress.org/trunk@5463 9866e705-20ec-0310-96e7-cbb4277adcfb
Use `Topic Tag` term for singular topic tag context in 'at a glance' dashboard metabox. Fixes #2544

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5464 9866e705-20ec-0310-96e7-cbb4277adcfb
In `bbp_do_ajax()` use `get_option( 'html_type' )`.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5465 9866e705-20ec-0310-96e7-cbb4277adcfb
Simpify `ABSPATH` checks to pass coding standard sniffers that look for brackets on comparisons.

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5466 9866e705-20ec-0310-96e7-cbb4277adcfb
Only add the `s` argument to queries if `rs` or `ts` are set in their respective topics & replies queries.

See #2607, #WP11330, [WP28623] [WP28612], [WP28804].

git-svn-id: https://bbpress.svn.wordpress.org/trunk@5467 9866e705-20ec-0310-96e7-cbb4277adcfb