Adds shortcuts for undo/redo for thangs tab view
Adds initial modal and view for terrain generator
Adds randomise option to dropdown on editor page
Cleans up some css for terrain generator modal
Adds code for passing randomised thangs to thang view
Random thangs are now created and positioned in the thangs view
Adds randomiseFloor and randomiseBorder functions
Removes console logs
Big terrain generator commit -
1.Adds method for randomising decorations/doodads
2.Creates presets
3.Adds thang clusters which can be used to create presets easily
Removes console logs
Merge pull request #1289 from jayant1992/terrain-generator

Terrain generator