Added some tweaks in map editing and town palette

- Added shortcut to Town Palette (Ctrl + T)
- Added icon to Town Palette
- Now you can use middle mouse button + ctrl to reset zoom
Merge branch 'tweaks' of https://github.com/Crypton33/forgottenmapeditor

* 'tweaks' of https://github.com/Crypton33/forgottenmapeditor:
  Added some tweaks in map editing and town palette