Completely changed the way unit conversions work by using blocks rather than a set multiplier. This will help with more complicated and customized conversions.
CUUnit’ baseMultiplier has been replaced with unitConversionBlock which accepts a double representing the current value in current units, and returns the converted value in base units
Merge pull request #3 from mrabenhorst/issue-1-change-unit-conversion-to-block-methods

fixes #1