WIP: mne edf2fiff

Not ready for review yet.

I had a bit of extra time on the train this weekend. For the most part, I have gotten the bulk of this done. I'm facing a problem with EDF+ because I don't have a copy of the annotation file to complete it. I've noticed some precision differences between the mne binary converted bdf and the one that I am generating. I am checking against the original code to make sure that I am not doing anything wrong.

A few questions for @leggitta or anyone familiar with edf+ or bdf. So, the edf (generic name) files have the channel names built in. Is this customizable within edf or are these set by the system? Parsing the EEG channels from the EOGs, Aux, and Stim channel would be/is tough without some system imposed. Also, I don't know whether I should rely on certain naming conventions. Relatedly, is the stimulus channel always last? Also, I'm having a problem interpreting the stim channel in bdf; the values being returned aren't readily interpretable.