Do not mutate options hash passed in, clone it to a new object

This had unintended side effects #29

Refactoring/cleanup of Promise usage

0.4.0

Update package.json

Sourcemap support for LESS 2

0.3.0

Version bump to 0.3.0

Replace Less 1.x for Less 2.x

0.2.0

[README] Adjusting Brocfile example