prepare splashscreen
[refactoring] refactor CartridgeListAdapter
[refactoring] remove useless code
[refactoring] improve CartridgeList, added sorting and segments
extend cartridge list header (right text element)
[refactor] cartridge list (fetch cartridges)
scan file system (storage card) for cartridges
[refactor] file collector
[refactor] create neasted class for cartridge collector listener
[refactor] extract method createContextMenu, onContextItemSelected and
onListItemClicked
remove class FetchCartridge and FetchCartridgeListener
improve header titles
extends preferences for cartridge search
[refactor] move FileCollector and FileCollector filter implementations
in a extra package
update name
added action for new preferences
added new preferences for file scan
[bugfix] fix wrong preference type / wrong preference