FileField and FileInput

[jokull]

Can mitsuhiko or someone else have a look at my code over at http://github.com/jokull/fungiform/commit/46c3215d1ce80bf5dc7cc4ea9851c2f5337c0827 and http://github.com/jokull/flask-fungiform/commit/0930c3021597e6e7d54817dedcf526b51ad05e3f

The basic idea is that FileFields should not be handled by a forms library until you know which framework it's tied to. Flask-Fungiform presents this opportunity!

The only change to fungiform itself is the enctype. Basically I've allowed fields to "upgrade" the form to multipart if you set that attribute to True on the field.