SD-672 user preferences - fresh back-end support implementation
fix(ingest): add base ingest service class

fetching an item from ingest is calling service to get an updated
version of item. this might not be applicable to some providers
so there is a base class that handles this.

SD-654
Merge remote-tracking branch 'anca/preferencesBranch'
fix(preferences): make tests pass
Merge pull request #266 from petrjasek/master

fix(ingest): add base ingest service class
Merge pull request #267 from petrjasek/fix-preferences

user preferences