3577999 : Extend Namespaces enum with common prefixes

common prefixes are virtually never changed or assigned in any other way, without making them mandatory

add inUse boolean parameter to Namespaces to avoid legacy namespaces
GITHUB-10 : Remove dependency on OpenRDF Sesame
GITHUB-10 : Add isBuiltIn
GITHUB-10 : Apparently Java doesn't like that style
Merge pull request #27 from ansell/GITHUB-10

3577999 : Extend Namespaces enum with common prefixes