Get TableMap class name from Peer class instead of concatenating

I think it is a bad idea to generate the TableMap name on demand in the
DatabaseMap. Instead it would be a good idea to read it from the Peer
class. In that case it is possible to change the TableMap class name
completely by overwriting the builder.

For Namespaces I fixed the unit tests that failed after the first commit. UnitTests run on travis for php 5.2 to 5.5.