Tradingstrategy

- Closes 108 - Plotting documentation
- Some updates to analyzer docs
- Further refactoring/improvements/corrections to the analyzers

- Pyfolio integration
- Refactoring/reorganization of analyzers

- Correct filler implementation in the broker to consider order side for the
value returned from a filler
- Extend volumefilling sample to cover sell and repetition scenarios

- Added support for volume filling strategies in the broker
- Added 3 volume fillers: FixedSize, FixedBarPerc, BarPointPerc
- Added broker and fillers to the docs
- Added TimeReturn to the Analyzers reference
- Added DaySteps filter and sample to downsample a day bar in open + rest

- UltimateOscillator added. Requested with ticket 103
- VisualChart Live Data Feed/Trading integration
- Add YahooFinanceData (online) to formats supported by btrun

- InteractiveBroker Live Data Feed/Broker
- Rework of many internals to support live feeds
- DateTime Management (timezones) support added
- Extra Rework of Resampler/Replayer to support live feeds and earliest
possible bar delivery