add readonly flag to columndefinition
complement table interfaces to support adding readonly columndefinitions
Merge remote-tracking branch '52n/master' into feature/readonly-columns
Merge remote-tracking branch '52n/master' into feature/epsg-codes-with-latlon-ordering-to-runtime-database
Merge branch 'master' into feature/epsg-codes-with-latlon-ordering-to-runtime-database
Merge branch 'master' into feature/readonly-columns
Merge branch 'feature/epsg-codes-with-latlon-ordering-to-runtime-database' into develop
Merge branch 'feature/readonly-columns' into develop
Merge remote-tracking branch '52n/master' into develop

Conflicts:
	core/ilwisobjects/table/basetable.cpp
	core/ilwisobjects/table/basetable.h
	core/ilwisobjects/table/flattable.cpp
	core/ilwisobjects/table/record.cpp
	core/ilwisobjects/table/record.h
declare unique pointer for XPathParser
add readonly flag when adding columndefinitions
remove obsolete forward declaration
add alternative addColumn method
Merge branch '52n/master' into develop
Merge pull request #72 from ridoo/develop

Merge features and minor fixes