logic: load 6 skybox textures when shader gets used by scene, don't unload dynamically, just on 'flush'
texture browser only uses normal preview image and doesn't trigger potentially heavy box loading
also fix R_ResampleTexture for [2+x upscaling
binds...
* m1 + shift drag: snapped modes of manipulators:
scale free: scale two axes synchronously
* m2 in entities creation menu: change classname; ctrl + m2: change classname, don't close menu
* ctrl + m1 in entities creation menu: create entity, don't close menu (+offset every next entity by 8u or gridsize, if > 8)
misc...
* fix: laggy selectors, manipulators in mlook mode
* scale free->snapped mode: constrain to two axes, most perpendicular to view direction (i.e. works for two axes in 3d too)
* scale free->snapped mode: use min move delta for scale (was max = hard to scale down); fix ZY projection case
* fix: pointfile was considered as shown, when trying to load missing one
* entity inspector->EntityProperties treeview: Tab keypress = focus Key field
* 2x2 layout: allow gtk to handle separators positions; fixes: unmaximize wnd, maximize = horizontal separators > center
fixes: unmaximize wnd = not updated views glwidget positions on some systems
* fix: paint selector, selecting occluded faces
* camera->field of view option
* wider Texture Gamma preference range
* wad games->texbro treeview: do not group names, using underscore; fixes crash on loading parent; fixes mess if path contains underscore
* fix: do not quit freelook on autosaving
* entity creation menu has ability to be 'tearoff'
* wad games: fix TextureBrowser_ShowDirectory crash on loading common dir (can cfg to load .wad), on loading containing dir (do nothing)
* wad games: fix crash on selecting a shader (not a plain texture) in tex bro
* wad games: more reliable filterbar texturing defaults
* shader for 'caulk new brushes' and 'clipper uses caulk' options is optional via 'shader_caulk' option in .game
