Added import button and disabled export

Keep public backup safe
Moved external storage management to Persistence
Import/Export give feedback on special textview
Fixes and introduced localisation
Half data trains, half data can be fed to belief
My small TODO for data collection
Made timestamp public for Measurements

It is final anyway
Moved functionality from APMatrix to Localisation
Moved dataset spliting to Localisation
Bugfix: Belief crashed when meeting unknown APs
Moved cell indexing to Localisation
Automated simulation of localisation

Produces convergence history
Bugfix
APMatrix can return PDT for specific location
Evaluation
Merge branch 'master' into Bayesian-Model
Merge master into Bayesian-Model
Added javadoc for public fields in Measurement
Accomodated for refactor of measurement class