`py-indent-or-complete' fixed

Don't call completion from within a word
Chars \r \f added as end/beginning of word
`py-shell', better support of `py-fast-process'

If `py-fast-process-p' is `t' or optional argument FAST-PROCESS, connect
a Python-process to a buffer not in comint-mode
`py-shell', `py-fast-process' again
restore previous version
added:
  test/py-bug-numbered-tests-1.el
  test/py-bug-numbered-tests-2.el
  test/python-mode-tests-1.sh
  test/python-mode-tests-2.sh

removed:
  test/python-mode-tests.sh
  test/py-bug-numbered-tests.el
adding tests, again
py-split-windows-on-execute-p kill windows, lp:1359081

fixed

Setting new customizable `py-always-split-windows-p' to `t' will
display every new shell by splitting

Default is nil, keeps current behaviour displaying just one shell
alongside with source

When `t', split current buffer's window unconditionally
Split according to settings of `split-height-threshold', `split-width-threshold';
as far as `window-min-height', `window-min-width' permit