issue #25: Range.js, refactor, rename field.
issue #25: Doc cleanup
issue #25: initial implementation of new RangeMi and RangeKm parameters.
issue #25: minor fix, warnings
issue #25: units refactor
issue #25: refactor, only call/display info window from one place now.
issue #25: elevation is undefined for custom markers, handles this
issue #25: show elevation in units corresponding to user selected range circle unit.
Merge branch 'issue_25'