Substantial changes to create the fastRead method

As you may know, the bower API is extremely slow (about 1 second on my machine), which becomes problematic when you are using a tool like browserify watchify which is continually recompiling your code. I implemented a much faster custom resolve algorithm that should mimic pretty closely what the bower API is doing.

Also, I changed the return value to an absolute path rather than a relative one. This worked better for me in a dependent library I'm working on, but I can obviously understand if you would still prefer relative paths.