Fixed, Texture Browser Form: well, I broke "Tab" key functionality again (in previous commit)...
Maintenance: changed curly braces style to match DB2 one (hopefully not breaking anything in the process...).
Maintenance: changed private method names casing to match DB2 one.
Configurations: all 64 game configuration are now available by default.
Game Configurations window: game configurations can now be disabled. This setting is mostly cosmetic. When a game configuration is disabled, it won't be shown in "game configuration" dropdowns in New\Open Map Options and Map Options windows. If a map's .dbs file specifies a disabled configuration, it will be picked as a map configuration anyway.
Linedefs mode: vertex insert preview logic used Highlight range instead of Stitch range (which is used when draw mode engages).
Visual mode: double-sided middle textures were not selected when using "Select" action with "with same texture" modifier.
Textures: some optimizations in patch blending code.
ZDoom ACS script configuration: added definitions for StrLeft, StrMid and StrRight functions.
Sectors mode: optimized sector highlight rendering logic.
Sectors mode: optimized sector effect/tag labels update logic.
Geometry tools: optimized several core functions.
Hints for current editing mode can now be displayed when nothing is highlighted (currently the hints are shown only in Draw Geometry mode).
GZDB is now build with LARGEADDRESSAWARE flag, which increases amount of RAM GZDB can use from 1.4 to 2.8 GB.
Added two new type handlers that can be used in UDMF ('Thing Type' and 'Thing Class')
Polished the browse icons and browse buttons.
Added more events for plugins to intercept.
