Fixed, Map Analysis mode: fixed a crash when trying to dissolve an invalid sector when one of it's linedefs referenced it on the both sides.
Fixed, Sectors mode: fixed incorrect undo description when deleting sectors.
Internal: joined declaration and assignment of some more variables.
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.
Map Analysis mode: "Check overlapping lines" now finds duplicate linedefs (e.g. when 2 lines have the same start and end positions).
Map Analysis mode: added "Check overlapping vertices" check. This will check if a vertex is on top of a linedef or another vertex.
Some cosmetic changes in Tools and BaseVisualMode.
Updated zspecial.acs