make xmlapi for primitive types generic

alib2data/src/XmlApi.hpp

alib2data/src/primitive/Bool.cpp

alib2data/src/primitive/Bool.h

alib2data/src/primitive/Character.cpp

alib2data/src/primitive/Character.h

alib2data/src/primitive/Integer.cpp

alib2data/src/primitive/Integer.h

alib2data/src/primitive/PrimitiveFromXMLParser.cpp

alib2data/src/primitive/String.cpp

alib2data/src/primitive/String.h

alib2data/src/primitive/Unsigned.cpp

alib2data/src/primitive/Unsigned.h

alib2data/src/sax/FromXMLParserHelper.cpp

alib2data/src/sax/FromXMLParserHelper.h