contrib: split pypats list in check-code.py This is a part of preparation to apply checking with check-code.py on code fragments embedded in *.t test scripts. Ideally, all patterns in "pypats" before this patch should be applied on not only normal *.py files but also code fragments embedded in *.t test scripts. But fixing test scripts for some patterns requires many changes, and has less profit than effort. Therefore, this patch splits pypats list into two below: - commonpypats, which are applied on all (= including code fragments embedded in *.t test scripts) *.py files - pypats, which are applied only on normal *.py