Rename base_dtype to base_type
Rename base_bytes_dtype to base_bytes_type
Rename base_expression_dtype to base_expression_type
Rename string_dtype to string_type
Rename struct_dtype to struct_type
Remove stale file ndobject.cpp
Rename *_dim_dtype to *_dim_type
Rename date_dtype to date_type
Rename builtin_dtype to builtin_type
Rename the remainder of *_dtype to *_type
Some more _dtype to _type renames that were missed