Implement some more callbacks

partially revert r1fba650c2aa4 on misc/physfs/CMakeLists.txt which randomly set true and false variables

Delete poller when game is over

less linking needed, raise minimum_osx_version when videorec is enabled

Merge with default

hides the 'email' prompt on the feedback page (as that doesn't work, so it's a misleading/useless feature), makes the "please add your email" text a little nicer and more noticeable, and makes the "feedback" and "downloadable content" buttons on the main menu a little bit larger, and more clickable.

Some fixes

Unbreak build