Core/Spells: Channeled spell pushback is now affected by haste
Core/Auctionhouse: Hide known recipes when the Usable box is checked in the AH

By y1x2 @ cmangos

Closes #12247
Merge pull request #12885 from mik1893/channel_pushback

Core/Spells: Channeled spell pushback is now affected by haste

Closes #12879