Split manifest build methods
Split asset path for great sanity

Makes assets aware of difference between directory and basename. Removes need
for gsub nonsense in package#copy!
Tidy fileutils and pathname requires
Add concatenated assets to manifest

Manifest is now a true representation of all source and result files.
Make rack reponse bodies arrays

Compliance! :beer:
Basic JSON API

* Changes /manifest path to /packages
* /packages/:name
* /packages/:name/:state