Metric Time Support

Add support for Metric Time, sometimes referred to as Decimal Time.

This is the representation of time in the form of days, decidays (1/10 day), centidays (1/100 day), millidays (1/1000 day) and microdays (1/10000 day).

This would mean adding expression variables for these units (ie {dd}, {cd}, etc) and rotation values, as well as adding a "numbers ring" type with 1-10.

http://en.m.wikipedia.org/wiki/Decimal_time

http://www.lifehacker.com.au/2012/11/why-its-time-for-the-decimal-day/