Make files_for return file names

Make `Projections#files_for` return the file names that `#file_for`
would expect, unless a `:verbose` option is passed, in which case it
returns full paths still.

Refs #2
Add --verbose option to prj list

Refs #2
Merge pull request #15 from glittershark/gh/2/prj_list_file_names

Make prj list return file paths