<DA-161> start take picture with xamarine.Media
<DA-161> save photo to local storage
<DA-161> Merge branch 'unstable' into DA-161
<DA-161> add methods for photo condition to controller
<DA-161> fix 349 again
<DA-161> change ios app storage to documents folder
<DA-161> start implement uploading files to server
<DA-353> rewrite condition as assertion
<DA-353> prepare to move code to separate controller
<DA-353> find media file and correspond timeline enry by pressed image url
<DA-353> fix compile errors
<DA-353> Implement Mediafile pager
<DA-353> start implement new screen and transitions
<DA-353> implement transitions between full screen and drallo details
<DA-353> start use full screen controller
Merge branch 'new_challengeEngine' into DA-348

* new_challengeEngine:
  added new challengeEngine with final map-features
Fix some of compile errors
fix all compile time errors except two that are related to assembly versioning
change ImageProvider to interface; fix some typos
extract IImageProvider to common code;
extract base class of ImageDownloader