Add script that will be used for releasing powerline
Push to upstream and do not use `release-` prefix
Add ability to run only the given stages
Add code to deal with raiagent overlay
Fix tests with  <psutil-2.0
Use pwd.getpwuid or getpass.getuser to get current user name
Join paths using more robust path joining function

Fixes #1087
Fix WM bindings tests
Fix UnboundLocalError in logger exceptions handling code
Raise exceptions that are not intercepted when testing

Thus problems like in #1087 will result in build failure.
powerline-python got renamed to powerline-vim
Merge pull request #1093 from ZyX-I/fix-tests

Some test fixes
Merge branch 'release-script' into develop