_khmermodule.cc cleanup

[mr-c]

• tp_name field of PyTypeObjects needs to include module name; dot separated; Example: khmer.Read
• rename all Python facing mentions of 'hash' to 'table' (and update Python code)
• remove _common_init_Type and refactor accordingly
• PyTypeObjects should be name khmer_${TYPENAME}_Type;
• all PyTypeObjects should be implemented as new style Python classes
• Type methods should use their type Object in the method signature instead of PyObject. Cast the methods to PyCFunctions in the PyMethodDef.
• Type deallocators should use their type Object in the method signature instead of PyObject. Cast the method in tp_dealloc to (destructor)

Types to review

• Read_Type
• ReadParser_Type
• ReadPairIterator_Type
• khmer_KSubsetPartitionType
• khmer_KCountingHashType
• khmer_KHashbitsType
• khmer_KLabelHashType
• khmer_ReadAlignerType

[luizirber]

Working on it: #785

[ctb]

More or less done (#785, #1044) and the naming scheme stuff is punted to #872.