Added /batches resource
* BatchesResource for /batches
* BatchResource for /batches/{id}
Functional version of batches resources
* /batches => GET method
* /batches/{id} => GET method
* /batchrequests => POST method
* /batchrequests/{groupkey} => GET method (returns 201 or 202)
* needs revision before push
Message type parameter not case-sensitive

* e.g. GET /messages?type=aType is equivalent to GET /messages?type=atype
Amount in routed message resource entity is String

* in RM entity, amount field is of type String, not Big Decimal
Properly throw and catch "forbidden" exceptions

* the stack trace is not printed any more
Added entity managers as static final variables

* passing them as arguments to subclasses becomes unnecessary
handle 'data_changed' exception
GET /api/batchrequests

* returns a json array containing group keys (ids for resource)
* enables filtering by user
Changed batchrequest json fields

* added progress per batch
* added number of batches to be processed
renamed class to MtView
Audit code

* removed unused imports
* added javadoc
* auto format text