use mkdirp
findParentDirCached and dirExistsCached are unused

remove them and their tests
move last function in fsTools into the only place it is used
refactoring to use exports properly
use imageinfo library
move urlTools into separate library
move TransformQueue into separate file
duplicate require
rename AssetGraph to index
specify license in package.json
fixed accidental global
Merge remote-tracking branch 'slang800/master'

Conflicts:
	package.json
	test/bundleRelationsOneBundlePerIncludingAsset-test.js
package.json: Hardcode the version numbers of the mkdir and imageinfo dependencies.