ENH: faster + leaner ica_tests
ENH add decim param to ICA
ENH: add decim parameters to ICA
ENH/FIX: use RandomizedPCA for whitening

FIX: add intended changes
CLN: clean up tests
FIX: whitening
ENH: add recovery test
ENH : cleanup ICA internals + fix some tests
FIX: partial fix
ENH: improve scaling in new plots
ENH: improve epochs example
ENH add decim param to ICA
ENH: add decim parameters to ICA
FIX: HEAD
ENH: add bandpass filter to ICA example to better hit the ECG component