Add support for floating point boundaries

According to the W3C's documentation of the `range` input type [1], the
`min`, `max`, `step`, and `value` attributes may all be specified as
floating point numbers.

[1] http://www.w3.org/TR/html-markup/input.range.html
Merged jugglinmike-floating-point
Merged develop into jugglinmike-floating-point
Cleanup
Merge pull request #24 from andreruffert/jugglinmike-floating-point

Add support for floating point boundaries