Chocolatey Package

Resolves #7 

 - Build script now runs in Release mode
 - Added nuspec for Chocolatey package
 - Sexy ~~Metro~~ Flat UI Icon 

TODO

 - [ ] no license specified for the code. do you care?
 - [ ] got a better logo in mind to use for the package?
 - [ ] dev requires chocolatey in PATH to run `build.bat` - reasonable assumption?