see #8902 - Small performance enhancements / coding style (patch by shinigami):
- while -> foreach
- for -> for each

plus:
- cleanup of FileDrop class to make it more integrated into JOSM core + remove warnings

git-svn-id: http://josm.openstreetmap.de/svn/trunk@6104 0c6e7542-c601-0410-84e7-c038aed88b3b
see #8902 - Small performance enhancements / coding style (patch by shinigami):
- removed useles null checks before instanceof


git-svn-id: http://josm.openstreetmap.de/svn/trunk@6105 0c6e7542-c601-0410-84e7-c038aed88b3b
see #8902 - Small performance enhancements / coding style (patch by shinigami):
- set init size for lists when obvious

git-svn-id: http://josm.openstreetmap.de/svn/trunk@6106 0c6e7542-c601-0410-84e7-c038aed88b3b