fix breifing window/game over screens and menu transitions
remove unnecessary function
recenter options menu when confirming new resolution
fix lift voxels
hide invalid options in new battle (when opening)
allow ammo to define bullet sprite

will override weapon's bullet sprite.
fix door opening behaviours

both in pathing and in door opening
fix AI reserve

< != <=
Update Changelog.

5000 commits to OpenXcom, and what a journey it has been.
so many bugs squashed, so many features added, so much vanilla flavour.
thanks go out to all our contributors, supporters, translators, followers,
fans, friends, testers and players.
without all of your passion and enthusiasm, the project might never have
made it this far.
capital letter consistency.
remove 8bit
re-fix 541

be less obtuse, and handle it better.
fix audio mix
Changed Sell Manufacture from an option to a toggle.
Fixed UI bugs.
fix kneel reserve/mc/probably tank issue
Added reaction fire medal
Installer: Hungarian language added.
Added Purple Heart and Crimson Heart medals
Added Order of Glory commendation