* Added time shifting and secondary period averaging so that all 4 Ichimoku HLM lines can be created.
* `Current = 0` option to clarify user intention. Turn off to support Ichimoku ordinal indexing (1==1st), instead of the natural natural language / array indexing (0=1st) that users would expect to enter.
* `Into Past` option. Natural offset direction is toward future. Pinescript direction is the opposite. Use this to project into past by default (i.e. `- => Future`).