ENH: Better error info
API: Move estimate_rank function out of raw
ENH+FIX: Making CUDA resampling more efficient, fixing DC/Nyquist error
ENH: Minor speedup
STY: Use "copy" instead of "overwrite"
FIX: Missed copy arg
Merge pull request #448 from Eric89GXL/epochs-error-info

ENH+FIX: Epochs error info, fixing / making CUDA more efficient, refactoring rank computation function