Initial copy of Yahoo! Finance to a new plugin to be changed to be used with MEEF.
Additional changes for the new data provider.

-Renamed some classes which are going to remain
-Renamed the plug-in to point to MEEF instead of yahoo!
Added backend processing support
-Added parsing of a MEEF line (using the new API from 2006)
-Added download of a single MEEF file from historical quotes but without filtering.
Merge branch 'master' of https://github.com/fairmat/MarketDataProviders