Progress towards tile selection / placement

- Removed forms, this wasnt working as I intended.
- Added new basic layout to frmMain, may need adjustment as new items
are added.
- Resized renderwindow to fit new form layout.
- Added layer selection.
- NOTE: While layercount is still an internal variable, adding new
layers wasn't working out as planned. But can easily change map format
to contain more layers in future.
- Added proper tile placement handler, no more crashing.