Temporaly removed area/length/volume from doc.
Removed exception doc from here
NotFoundException -> Exception
Removed outdated info about id/uuid types
Spelling
Uisng uuid4 instead of uuid1
Changed type (and pattern) of get_xxxx exceptions
Default values in the constructor
Removed constructors for edge,face and cell, as they are the same as the baeclass
PyFlake & Pep8 Erros and minor mistakes
More corrections, changed the way the tests objects are created.
Unused include