* Introduce the 'css' task - this will give us flexibility to do things
in future rather than relying on the inbuilt 'less' task (e.g. sourcemap
generating task which doesn't run by default)
* Introduce 'amd' task which runs only amd tasks
* Introduce 'js' task which runs all JS (amd/shifter) tasks
* Tweak the ordering so that slow shifter always runs last (useful for
people like me who forget to specif the task)
Previously we were using recess to build bootstrap base as it was what
was used by the original project. But recess is no longer maintained.
Now we use grunt for building js, it makes sense to use it for less too.
(If you really don't want to use grunt, you almost certainly can just
use lessc -x as it uses the same less.js on backend).
Unfortunately, this is not perfect yet. It will build the entire
repository every time - which takes a while because it builds all the
yui modules (On linux it correctly only builds whats in the current dir).
