Updated site compilation to respect exact paths for files.

Added root input dir to view object to better handle exact paths of files to be
processed and moved during site compilation.

Optimized site view objects to cache the calculated output path so it doesn't
have to recalculate it each time it is called.
Merge branch 'feature/issue20' of git://github.com/sumpygump/phrozn into feature/integrate-issue20
Added Has\InputRootDir interface
Fixed typo
Merge branch 'feature/integrate-issue20' into dev