Allow tracker to start without address
Allow trackerless files
Merge branch 'trackerless' into socket-open
Allow trackerless files
Merge branch 'trackerless' into socket-open

Conflicts:
	src/main/java/com/turn/ttorrent/common/Torrent.java
Do not announce when tracker list is empty
Merge branch 'trackerless' into socket-open
Do not announce when tracker list is empty
Merge branch 'trackerless' into socket-open

Conflicts:
	src/main/java/com/turn/ttorrent/client/announce/Announce.java