Some windows specific fixes
Do not proceed windows, if HOME and USERPROFILE are set to different
values

This leads to unexpected behaviour, for example magit does not pick up
global git config
Install powershell mode on windows
Set ispell-program name to whichever spell checking application is available
Check 'make' and 'python' are available before installing ropemacs

These might not be available on windows
Jedi might require a restart of windows, display a message saying so
Check ropemacs is installed before using it
Do not use ipython on windows, it does not seem to work properly with python-mode
Warn user, if there are spaces in path to inferior-lisp-program
Enable org-babel for graphviz, if graphviz is installed on system
Minor changes
Add graphviz mode
Temporary use ';' to concat system vars on windows
Add some recipies
Use custom function to auto-install language modes
Do not use exec-path-from-shell on windows
Warn if phpmd is not installed
Associate racket buffers with scheme mode
Make scala config more robust
Check availability of racket/guile before starting geiser