Refactor command related code in modules

Introduce org.projectmaxs.module.<name>.commands package, SupraCommand
and SubCommand. The code of the command is now within it's own class in
the 'commands' package. MAXS-7
Introduced Handler for java.util.logging
Update MTM to a version that replaces Android Log with JUL
transport-xmpp: log a warning in case of non-master JID message
transport-xmpp: Log TransportService onStartCommand

Recently we started to see behavior like this:

03:17:57.191 I/ActivityManager(  677): Process org.projectmaxs.transport.xmpp (pid 23152) has died.
…
03:19:36.133 I/ActivityManager(  677): Start proc org.projectmaxs.transport.xmpp for service org.projectmaxs.transport.xmpp/.TransportService: pid=6370 uid=10132 gids={50132, 3003}
…
03:21:08.000 I/ActivityManager(  677): Waited long enough for: ServiceRecord{4312d818 u0 org.projectmaxs.transport.xmpp/.TransportService}

Maybe this extra log information provides a hint about why the
TransportService seems to do nothing.
module-makefile: .settings should respect BASE
module-makefile: Make relative symlinks for .settings
Improved JULHandler
transport-xmpp: Add support for XMPP Privacy Lists

Resolves MAXS-15
Update documentation

Add developer quickstart