README description and usage.  Added appropriate less dependency.

This is the basic writeup for the gem with requirements, purpose,
and design.  This locks in to the 1.x.x ruby-based less compiler
b/c that what this engine is for.
basic setup for libs and test suite

This sets up the libs, makes sure they can be required in appropriately,
and sets up the test suite.

I'm putting all this in its own commit to keep the upcoming commits
clean of this boilerplate stuff.
basic engine unit tests

Test the the input ext gets updated to 'css' and that the input
content gets compiled.

Pretty basic stuff.
dassets digest system test

This tests that running a Dassets digest with the engine registered
works as intended and digests the less source.
rework test suite to use a Factory for seed less and expected css values

Instead of dealing with a bunch of files on disk.  Trying to improve
maintainability.  No behavior changes here.
Merge pull request #1 from redding/kr-firstpass

FIrst pass implementation