FIX : increase test timer for buildbot in realtime
FIX : fix coreg import mess
weak dependency on psutil
FIX: Bad import
FIX: Bad import
FIX psutil
COSMITS psutil
ENH: adding rereference eeg channels function to raw.py and implementing test function. Implemented suggestions from Eric and Denis (pull request #795)
changed rereference function from a method to a function in mne/fiff/raw.py. Implemented suggested changes