Log Message:
Add LICENSE
Update to 0.3.2

Changes:
* Fix 16bit tiff output in stitching mode.
* Don't draw labels of mountains that are slightly off the image.
* Factored out ScanImage class.
* Fixed a nasty issue with float <-> double conversion introduced in 0.3.0.
* Add manual hiding / unhiding from right click popup menu.
* Moved NEWS to ChangeLog.