Fixed: changing brightness of upper/lower/middle sidedef did not update the whole sidedef brightness until 3D mode restart

Added dynamic light count = 256 for high end users. Fixed: incorrect attenuated<->subtractive light ordering caused invisible subtractive lights.

Added: primitive support for ZScript in the script editor (all classes in the current file are listed)

Added: basic support for automatic user variables from ZScript classes, currently only for int variables (as supported by GZDoom).

Reverted anotak's PR: it causes 'Cancel' button in Edit windows to automatically do undo or something similar, breaking maps completely

Speedup on opening properties windows

This reverts commit 4d9d1eda.

This reverts commit a3ff16ca.

actionmanager change

Fixed: links should now open in the default browser and not what GZDB thinks to be the default browser.
Fixed: ZScript parser should no more crash on severely invalid code.

Added: more magic to the autoalign/select neighbours logic; These functions should not anymore wrap around to the opposite side of two-sided linedefs, allowing you to select back and front sides separately using shift+click, and reducing infinite broken autoalign loops.

Fixed: long texture names are no longer activated for Doom flat images (GZDoom doesn't support these)