update version to 2.1.2-SNAPSHOT
fix cut of the last filename character when dropping file on a map
fix location for LinkedFiles

 - LinkedFiles are to be store with the map where thei are linked
add logging regarding linked files
Merge branch '2.1.2' of github.com:CompendiumNG/CompendiumNG into 2.1.2
file copying rework via NIO

 - new file copying utility method
 - use it for copying files when droping a file on a map and copying it into LinkedFiles
add filecopy test
Merge pull request #137 from maiklos/2.1.2

2.1.2