Added Wordpress, MongoDB, Laravel, Symfony, PhoneGap icons

This fixes issues #3, #4, #5, #6.

Also, I think the `with-build-scripts` branch should really be merged into master now.

I had an enquiry from someone adding to the Atom editor package `file-icons` who was confused because the version of `font-mfizz` in master is the old version.

If you like, you could add me as a collaborator on this project, and I could handle these actions for you?

Thanks in advance.