add - angular / node handshake done; file gets sent, converted, zipped, ...

...sent back
messed up with git so I made this new branch. 

- if we want to convert an entire directory, we'll need to rewrite some code in the $postFile service
- the controller is a bit on the heavy side, I welcome an organization discussion! Didn't really know where to put things now.

- file automatically uploads and downloads right back to your directory, so I'll have to figure that one out 
indentation, also you've added a static method "upload" to the instantiation function of the service. Not sure what the conventions are supposed to be regarding services/factory instantiation patterns, however if you want this to follow pseudoclassical style, you should either capitalize the variable name or return an object.