Updated SimpleTag & DataTag to have only "hasReference" & "removeReference" with "const string &id" parameter.
Fixed TestSimpleTag to use only "const string &id" version of "hasReference" & "removeReference"
Merge pull request #144 from balint42/fix_getter-setter

Final (alpha) fix of getter-setter patterns
Fixed all entity-handling setters to unset field or throw exception if empty entity passed.

The following setters are affected:

EntityWithMetadata::metadata 	(optional => unset field)
DataTag::extents		(optional => unset field)
DataTag::position 		(obligatory => throw runtime error)
Representation::data		(obligatory => throw runtime error)
Section::link			(optional => unset field)

Adressing issue #89
fixed bug in SimpleTagHDF5, implementation of TestRepresentation
Merge pull request #146 from jgrewe/representation

implementation of TestRepresentation and following bugfix in SimpleTag

LGTM
Fixing handling of empty strings by setters.

Adressing issue #89 three principles have been implemented:
-all setters that accept strings now throw a runtime error if the string is empty

The following setters change:

NamedEntity::definition
NamedEntity::name
NamedEntity::type
DataArray::label
DataArray::unit
DataTag::extents
DataTag::positions
RangeDimension::unit (also added "forceUpdatedAt();")
RangeDimension::label (also added "forceUpdatedAt();")
SampledDimension::unit (also added "forceUpdatedAt();")
SampledDimension::label (also added "forceUpdatedAt();")
Property::mapping (also added "forceUpdatedAt();")
Property::unit
Section::mapping (also added "forceUpdatedAt();")
Section::repository (also added "forceUpdatedAt();")
Minor bugfixes to prior commits of this branch.
Added an exception for empty string errors.
Merge pull request #147 from balint42/fix_setters

Fix setters
Fixed EntityWithSources: getSource overloads, addSource & sources-setter

getSource(const size_t index) & getSource(const string &id) now both check whether the requested source is part of the source_refs group and they use "findSources" to retrieve the source.
If either the source is not part of source_refs or is not found an empty source object is returned. (The latter being a behavior yet to be implemented for all instanes).
The sources(vector<Source> ids) setter is now reducing the given ids-vector to those ids that are actually found in the block. It does so by using a new "IdsFilter" struct with "findSources".
Thus also a new filter has been added a cosmetic changes to the "findSources" functions and function-docs have been made.
Merge pull request #148 from balint42/fix_EntityWithSources

Fixed EntityWithSources: getSource overloads, addSource & sources-setter