GMC Trend Filter

Avoid Fake Signals, and identify the trend.

How it works ?
- it calculates main trend direction by using the length that is user-defined. so you can change it as you wish
- then it calculates trend direction for each 9 lower lengths. if you set the length = 20 then the lengths are 19, 18,...11
- and it checks if the trend directions that came from lower lengths is same or not with main trend direction.
- it changes the trend color of the ribbon.