Users cannot delete their own topics or replies when respective capabilities are assigned

[netweb]

Users given either delete_topic or delete_reply capability cannot delete their own topics or replies respectively.

Confirmed and reported here: ​https://bbpress.org/forums/topic/delete-topic-function/

Hat tip @gusrb84 for the attached patch

[lgladdy]

I've hit this block today and would love to see this being added to the next release - it doesn't make sense that there is already a check for delete_reply and delete_topic but you can't actually apply that to a role!

[johnjamesjacoby]

In 5852:

Capabilities: add delete_posts mappings to delete topic & reply checks.

This changeset ensures that capable users can delete their own topics & replies, when these capabilities are explicitly allowed already.

Props netweb, gusrb84. Fixes #2685.

[netweb]

In 6265:

Capabilities: Fix inline docs copy pasta introduced in [5852]

See #2685