Added grunt-copy task to copy assets to public/lib

* looks like you had added /public/lib/ to Git, and afterwards added the path to the .gitignore
* first person to clone your repo is fine, as they'll get the /public/lib/ folder
* once they commit, that folder is no longer there so all other team members will be in a world of shit
* you could just remove the path from .gitignore, but that won't get around the issue that the files in /public/lib will never be updated
* added the grunt-copy package
* added copy task and added it as first step/task in default task
* I found it impossible to get a truly recursive files + folders copy working, hence having to copy every folder/sub-folder individually. Arse.
* without the punctuation option, it appends a fullstop (period...) to each file.  Odd.