Fix "hasObject" in "group": no exception if empty string passed.
No nullp, use none instead. Further bool operators in ImplContainer.

Abandon use of "nullpointer" and use "boost::none" instead. Add further bool behavior to ImplContainer. Adapt all test cases too.
Tiny fixes to ImplContainer & Group.
Merge pull request #154 from balint42/fix_group_and_nullp

Fix group exception and nullpointer use
Heavy rewrite of DataArray and Dimensions.

DataArray and Dimensions have been modified to implement final version of "optional" vs "obligatory" attributes.
createDimension and appendDimension do not exist anymore, instead createRangeDimension, createSampledDimension, createSetDimension, appendRangeDimension, appendSampledDimension, appendSetDimension have been implemented.
A private, templated _createDimension handles the actual creation of the Dimension entity. All getter & setter now provide boost::optional / boost::none if they are supposed to.
All test cases have been rewritten to work with the changes.
Implemented final optional vs obligatory attributes in SimpleTag.

SimpleTag now requires "position" as truly obligatory field, expecting it to be set upon construction. Therefore "createSimpleTag" & "getSimpleTag" in "Block" and the constructors have been changed.
All tests have been updated to work with new versions.
Minor fixes to prior branch (affecting Dimensions) included.
Implemented final optional vs obligatory attributes in DataTag.

DataTag now requires "positions" as truly obligatory field, expecting it to be set upon construction. Therefore "createDataTag" & "getDataTag" in "Block" and the constructors have been modified.
All tests have been updated to work with new versions.
Minor fixes to prior branch (affecting SimpleTag) included.
Major bug fix in "EntityWithSources" that prevented "Source"-getter from working!
Implemented final optional vs obligatory attributes in Representation.

Representation now requires "data" & "linkType" as truly obligatory fields, expecting them to be set upon construction. Therefore "createRepresentation" & "getRepresentation" in "SimpleTag" & "DataTag" and the constructors have been updated.
All tests have been updated to work with new versions.
Tiny renaming fix to make code compile with clang.
Merge pull request #156 from balint42/fix_optional_obligatory_1

Heavy rewrite of DataArray and Dimensions.
Implemented obligatory "type" attribute in NamedEntity ctor.

NamedEntity now requires "type" as truly obligatory field, expecting it to be set upon construction. Therefore numerous instances of its' use had to be modified.
All tests have been updated to work with new versions.
Removed all tabs.
Final minor fixes to getter & setter, new "MissingAttr" exception.

In particular fixed bug where obligatory getter would not throw error when attribute or entity was missing.
Introduced new exception "MissingAttr" to be thrown when an obligatory getter does not find required attribute.
Fixed some setter not throwing messages, in particular fixed "link" setter that would remove attribute falsly.
Homogenized existence of "hasXYZ" methods, removed where necessary.

"hasXYZ" methods now exist for every attribute except for optional attributes with the simple pattern "getter:attribute(), setter:attribute(...), deleter:attribute(none_t t)". For those "hasXYZ" has been removed where existing, since "attribute()" can be used instead.
Merge pull request #157 from balint42/fix_optional_obligatory_2

Fix optional obligatory 2
Merge pull request #158 from balint42/fix_obligatory_getter

Fix obligatory getter
Merge pull request #159 from balint42/fix_hasXYZ

Fix existence of hasXYZ methods
checking only the last commit makes it much easier :)
Finishing tests by adding some missing deleter test.
TIny bug.
Merge pull request #160 from balint42/fix_tests

Finishing tests by adding some missing deleter test.