Handle filenames with 'file://' shema, in getFileName method

[mathiasjakobsen]

Will fix bindings for use with Electron.

Fixes #29

[E3V3A]

@TooTallNate Please merge!

[cinan]

+1

[ViliusSutkus89]

@mathiasjakobsen Thanks for the patch, solved one of my problems.
However I ran into another one. fileName being file schema encoded means all the special characters are encoded too. Including spaces. C:/Program%20Files/
Ended up using "file-uri-to-path" module
ViliusSutkus89@3953f2a

[TooTallNate]

Thanks @mathiasjakobsen and @ViliusSutkus, I've merged your changes in d0bd6f8.