Many changes.

* Added comment for Eft command in vimrc.
* Added configuration for 'singlecomplie' choosing python3 as default
  interpreter.
* Added a comamnd 'Pr' to run current python script on windows, and echo
  the output back to vim' command line space.
Merge branch 'linux-win32-neobundle' of https://github.com/Mudox/vim-config into linux-win32-neobundle