Linear Regression Channel [jwammo12]

This is a non-repaint version of the built-in linear regression indicator in pine. It creates moving bands where the current bar matches the built-in Linear Regression indicator exactly (see screenshot). The key to replicating the built-in function is calculating the std deviation across the length of bars away from the current Linear Regression line, as opposed to the linear regression line that would have been calculated at the historic bar.

Release Notes:

update to version 3