1.3

###Main changes are:

-Paired list did not work when HC-06 ist not the first in list
-Calibrate button added, no need for manufacturer any more
-Disable reset and calibrate buttons when busy
-New status bar showing BT link status
-Some fixes to stop tasks on destroy and ensure BT is closed
-Show actual max/min limit values in buttons
-Values of chord, min and max are stored in preferences, no need to reenter when app ist restarted
-German language support
-Update html documentation
###Open issues:

not fully happy with BT connection, needs many seconds to connect. Not 100% reliable connect, but stable onec connected
Automatic BT reconnect not working. But return to main dialog and back to throw gauge reconnects.
link status is combined for two sensors, not perfect yet
angle calculation not 100% when offset occurs, e.g. angle hops between +3.0 and -3.0, without going trough zero, looks strange. But Reset can be used.