EHN: support for meegpipe's .pset/pseth files
FIX: forgot to add Fs to info
New preference file: opt_vici
Avoid warning when loading .pset/.pseth files
Clear persistent var associated to .pset/.pseth file
Potentially reads mff files faster
Explicitely mention .pseth as possible data format for new dataset
Merge pull request #1 from germangh/master

Support for meegpipe .pset/.pseth files, reads faster mff files