Added allTilesLoaded() method to UnfoldingMap.

Now two mechanisms exist: One listener/callback method (tilesLoaded()),
and one boolean flag (allTilesLoaded()).
Added LargeMapImageUtils to store larger-than-screen images (for print etc).
Make the MarkerManager's attributes protected.

Allows for easier subclassing of MarkerManager.
Merge pull request #67 from chmullig/master

Made more MarkerManager's attributes protected, to enable more flexible sub-classing.
Merge branch 'master' into develop
Merge branch 'develop' into feature-processing2

Conflicts:
	examples/de/fhpotsdam/unfolding/examples/image/LargeMapImageSaveApp.java