added some more serializers and removed api.fields
Merge pull request #5 from vplme/dev

Filter fields ActivityListSerializer
added verry basic serializer for transactions
Merge branch 'master' of https://github.com/Murrx/OIPA
fix build error
fixed some mistakes i introduced in activity.serializers after i removed fields.RootField"
added factory and test for AidTypeSerializer
Merge branch 'master' of https://github.com/Murrx/OIPA into dev