TRUNK-4109: Get observations by accession number

org.openmrs.api.ObsService#getObservations and
org.openmrs.api.ObsService#getObservationCount are now overloaded to support
specification of accession number.
If specified, only observations (or their count) with matching accession
number are returned.

See https://issues.openmrs.org/browse/TRUNK-4109
TRUNK-4109: code review: remove duplicate @should

Removing @should annotations for UTs of the original methods.
The new methods shall only be tested for providing the accession
number-specific functionality.
TRUNK-4109: UTs now use most general interface

Unit tests for org.openmrs.api.ObsService#getObservations and
org.openmrs.api.ObsService#getObservationCount now use the most
general methods (including accession number criteria specification).
TRUNK-4109: Get observations by accession number

org.openmrs.api.ObsService#getObservations and
org.openmrs.api.ObsService#getObservationCount are now overloaded to support
specification of accession number.
If specified, only observations (or their count) with matching accession
number are returned.

See https://issues.openmrs.org/browse/TRUNK-4109
TRUNK-4109: code review: remove duplicate @should

Removing @should annotations for UTs of the original methods.
The new methods shall only be tested for providing the accession
number-specific functionality.
TRUNK-4109: UTs now use most general interface

Unit tests for org.openmrs.api.ObsService#getObservations and
org.openmrs.api.ObsService#getObservationCount now use the most
general methods (including accession number criteria specification).
Merge branch 'master' of ssh://github.com/vencik/openmrs-core

Conflicts:
	api/src/main/java/org/openmrs/api/ObsService.java