- Msys (Windows) doesn't have `grep -o` support; using `sed` instead -- we're using the bugger already anyway. Also added `make version` target to show the decoded version to help diagnose grep/sed trouble on any platform.

- augmented Makefile to produce the latest LESS sources in build/less.js when running `make latest`

- default `make` now builds the `latest` target (build/less.js), runs the (NodeJS-based) tests and benchmark.