Windowkill 3.1.2 update

[h2]New Features[/h2] [list] [*]Added a new language, Vietnamese [*]Added "v-sync" option [*]Added "limit fps" and "max fps" options [/list] [h2]Changes[/h2] [list] [*]The game now saves a backup of all the save files (located in "%appdata%\Godot\app_userdata\windowkill\backup" or "~/.local/share/godot/app_userdata/windowkill/backup") [list] [*]This is a safety measure in case anyone runs into issues with Steam Cloud [/list][*]Language list is now sorted [*]Spiker no longer teleports while laser is active [*]Spiker no longer shoots while teleporting [*]Obliterate now clears slime trails [*]Changed visuals of dependent options [/list] [h2]Fixes[/h2] [list] [*]Fixed :)'s pointers behaving sporadically at lower framerates or high speeds [*]Fixed sweeper coin spawn location using bastion [*]Fixed zephyr's dash pushing window when detached [*]Fixed jumpy behavior when dragging some non-movable windows [*]Fixed windows not grabbing focus when they should (e.g. after closing shop/options window) [*]Fixed backing window sometimes appearing in front of some windows [*]Fixed end of timed mode unlocks not unlocking sometimes [*]Fixed drain not damaging tunnellers [*]Fixed "testers" section of credits being hidden [/list] <3