Latest release 6.3

Changes v6.1-3:
 - delete single POI
 - check for duplicate coordinates in category when importing POIs - POIs with equal coord are removed
 - fixed KML format import + iGo (KML) support
 - remember last file type in POI file selection dialog
 - small bugfixes
 - SQLite engine speedup
 - clear icon table - removes all unused icons and rebuild icon index from 1

ENJOY!