Backtrader-paperswithbacktest

- Add 3 new indicators (from 81): PivotPoint, FibonacciPivotPoint,
DemarkPivotPoint
- Add new function CmpEx
- Change plotinit to the intial stages of plotting
- Add plotinfo information to any LineSeries objects
- Implement LineActions Cache
- Implement Indicator Cache
- Cover resampling across midnight border 81
- Correct error in docs (concepts) 82
- Addresses 82 by only advancing indicators in runonce mode if the clock
has overtaken it
- Addresses 82 by having LinesOperations define and internal clock which
may not be the owner

- WeekDaysFiller sample for 76
- Implement new memory saving schemes. Addresses 74
- Additions/Refactoring to the intenal api offered to filters and internal
utils objects and removal of leftover prints
- Refactoring of replay/resample filters
- Some testing refactoring
- Support for cross-plotting across datas of different timeframes
- PivotPoint sample for 81

- Correct resampling/replaying behavior for calculating the delivery with
configured compression fator for timeframes ticks and days or larger.
Addresses 47, 77, 78
- Adapt resample/replay tests to improved resampling/replaying code which
delivers the bar 1 tick earlier
- Sample for bidask data to OHLC. Closes 78

- Fix broken data-multitimeframe sample
- Address 72 by improving _getsizing method which not also takes data as
parameter
- Fixes 77 by correctly calculating when the current session ends for the
last bar (when next session data is already in)

- Fixes 67 by having the Buy Sell Observer be displayed for all datas in the
system
- Improve support of live data feed resampling/replaying. Addresses comments
in 69 and 44
- Support safe division by zero RSI calculations. Closes 68
- Fixes 71. Single Lines (LineOperations in this case) don't get added to
the indicator mix for writers

- Improved detection in cerebro.resampledata of existing datas before cloning
- Added detection in cerebro.replaydata of existing datas before cloning