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.
Added Color Picker plugin
Point, Flicker and Pulse light animation should now look almost exactly as seen in GZDoom.
Fixed a bug when editing thing properties in Visual mode didn't update visual thing.
Fixed incorrect doom-style walls shading when sector has "lightcolor" property set.
Fixed "Index was outside the bounds of the array in CalculateNormalsAndShading()" error.
GZDoomBuilder will now show error message prior to failing.
