front: Add option for gles2rice fog effect

Also updated manifest and changelog in preparation for 2.4.0
front: Disable fog effect by default
build: Change version string to debug in manifest
front: Add interface for entering custom polygon offset
Using external coordinate for fog calculation

Fix fog banding issue on some devices.

TODO: Test if fog density is correct on every devices
Merge remote-tracking branch 'origin/master' into zelda-missing-heart-fix