Addressed issue prevent proper plate from being docked to.
yet another fix concerning crust density
Addressed issue in which continent-continent collision would not occur for micro continents.
Optimization of flood fill implementations.
Addressed issue causing gradual erosion of continental shield borders.
Reverting previous commit fixing microcontinent collision - while not technically correct, this performs docking behavior similar to what I want to see in the future.
Merge branch 'master' into gh-pages: bug fixes and optimization