`py--execute-base' use constant `py-windows-config-register'

`py--shell-make-comint' fixed

minor changes
`interpreter-mode-list' doesn't work as intended, lp:1355458

fixed

use `magic-mode-alist'

Thanks Phil Rufflewind
`py--shell-manage-windows' fixed

`py-shell' register `windows-config'

honor `py-exception-buffer'
`py--execute-base' fixed

Don't let-bind `py-error', needed outside

`py--postprocess-comint'

`py--shell-manage-windows' again: call it from just two places
`py--execute-file-base' fixed

`py-store-result-test' addedly
`py--execute-file-base' fixed

`py-store-result-test' added