added LabelSet and basic add/remove
added LabelSet and basic add/remove

fpieper/py2neo,technige/py2neo,nicolewhite/py2neo,pombreda/py2neo,technige/py2neo,pombreda/py2neo,nigelsmall/py2neo,technige/py2neo,fpieper/py2neo,pombreda/py2neo,nicolewhite/py2neo,nicolewhite/py2neo,nigelsmall/py2neo,fpieper/py2neo