Also run tests from the subdirectories
Don't force users to provide arguments
Remove the 'context' arg, as was done for 'function.js'
Add tests for node_fn.apply
docs for node_fn.apply
Add tests for node_fn.call

That are not really different from the ones for 'node_fn.apply'... Is
that a problem?
Docs for node_fn.call
Add tests for node_fn.bind
Add docs for node_fn.bind
The promiseRead example fits node_fn.bind better
Implement tests and doc for createCallback
s/node_fn/nodefn/g
Merge pull request #90 from riccieri/node

Document and test when/node/function