Added support for non-1.2 pixel ratios if view stretching is enabled (reported by Nash);  Fixed: map names in quotes were not recognized properly.

* Mouse selection threshold

* Cleanup

* Fix selection bug

- Dialog can't be resized anymore
- Dialog can be canceled by pressing the escape key
- Changed input boxes to the appropriate GZDB version, so steps and modifier key work correctly
- Added checkboxes to automatically fit the textures optimally based on the width/height of the line(s) in respect to the width/height of the texture
- Added input boxes to manually set a width/height pattern size of the texture that will be used when automatically fitting textures

Fixed: INHERITACTORPITCH was actually changed along with USEACTORPITCH...doesn't really make sense compatibility-wise but there it is. (reported by alekv)

Fixed: pitch formula was duplicated and not changed in one of the places. (reported by Ozymandias81)

Fixed: flipped +USEACTORPITCH direction for recent GZDoom versions;  this can be reverted by putting "buggymodeldefpitch = true;" in the game configuration for your specific projects if they are using old GZDoom versions.  Note: already added for Zandronum.

Fixed: render sorting issues with multiple translucent 3D floors next to each other on different heights

Fixed: the model should be Z-scaled to 0.83 even in unstretched view to ensure that models fit the geometry right (reported by Ozymandias81)

Fixed: texture copy/paste in the visual mode was detected as failed pasting and caused a beep. (reported by DOOMGABR, abbuw, Turret_Master)

Fixed: the old way of checking for GZDB's directory writability would not work in certain versions of WINE/Mono

Fixed: cutting a thing in visual mode would leave disposed BaseVisualThings in the selection. (reported by DOOMGABR)

Made Skulltag item sprites optional to support default Skulltag+Zandronum config without producing 100 errors