Infinity Indicator

If a timeline end date is set to infinity then this is now represented by a thin dotted line as the right edge of the timeline box border. This new infinity dotted line is weaker than the dotted line used for a circa date so it can easily be differentiated. The circa date dotted line has longer strokes.

---

*Integration Note: This "infinity-indicator" branch is derived from the "wcf-reset" branch that has already been submitted as a pull request.*