xmobarrc: added widgets weather, volume & mpd
xmobarrc: changed color of widget name for volume, weather & mpd
xinitrc: Run leechcraft at startup
Xmonad.hs, Xresources: added ncmpc hotkey + xresource entry
Updated readme
Actually use powerline in tmux
Use mod1 as mod key in xmonad.

Because steelseries 7g has bad position of mod4 key.