Updated: Mostly controls

Tweaked the controls a little, also added a few input methods.
Rough overview:
+  Added zoom
+  Added selection grid
#  Moved code
Detailed descriptions are in the respective script files.
ToDo:
#  Selection rectangle design
+  Implement path finding
+  Implement buildings
+  Implement unit interaction (with units, buildings, terrain)
+  Design and implement HUD, GUIs