New feature, backup workout in user specific directory

Preparations for the new feature to store backup files on the local disk
of all uploaded workouts.
Added new default setting BackupWorkouts to configuration
Setting backup directory for all newly created devices
Added workout backup functionality to file based devices (tcx+fit)
Modified FIT reader to parse for specific message in FIT file

It was necessary to get the activity type and date from the file to use
the new functionality backupWorkout. The callback mechanism that is usually
used to read fit files was too much overhead, so a way to read the next
fitMsg was implemented without using the callback.
Added backup functionality to Edge305 devices
Added change information to HISTORY file