Version 6.1.0

Improvements

 * Added Flak Cannon.
 * Can now edit the ground in single combat setup.
 * Fixed crash when opening ship editor or combat in fullscreen Windows.
 * Potential fix for mouse cursor misbehaviour of Windows.
 * The ground no longer sometimes falls down.
 * Grounding works again.
 * Improved Gatling Gun fire rate and damage.
 * Fixed incorrect placement rules for modules that need free space above.