Updated Core Data model to prepare activity types.

!!!Please export data before and import later. No automatic migration possible. !!!
Fixed export/import bug for tracks with pause.
Merge pull request #9 from webventil/logging-ui

Added support for pausing and resuming activity. Improved UI and localisation. Improved import and export.
Fixed errors with auto layout.
Merge pull request #11 from webventil/auto-layout-fix

Fixed auto layout warnings.
Merge remote-tracking branch 'upstream/master'