W_PyProxyGeneric -> W_PyGenericAdapter
 W_EmbeddedPyFunc -> W_PyFuncAdapter
W_EmbeddedPyMod -> W_PyModAdapter
 W_PyBridgeListProxy -> W_PyListAdapter
W_PyBridgeDictProxy -> W_PyDictAdapter
W_PyException -> W_PyExceptionAdapter
Update k_*definitions of php_wrappers.
Update PyPy interp-level class defs and rename PRef -> PHPRef.
rename py_wrappers.py and php_wrappers.py to their new names.
Tidy.
Rename strategies to better names.