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.
GZDoom Builder now uses SharpCompress.dll instead of SharpZip.dll.
Added PK7 archive support.
PK3 archives now load aprox. 40% faster.
Textures browser now shows Folder/PK3/PK7 folder structure.
TextureBrowserForm is now used to display both Textures and Flats.
ACS scripts from #include and #import directives are now shown in Script name/number dropdowns.
Fixed several cases when ACS scripts lists used in Edit Thing and Edit Linedef forms wasn't updated when they should've (i.e. after compiling a script).
