Slate living tutorial

[Matt Revelle]

A Slate tutorial has been started at: http://slate.infogami.com/ - it
is editable by anyone, so feel free to contribute.

The idea is to cover basic stuff: file I/O, string manipulation,
defining prototypes, delegation.  Leave out the technical
explanations, but provide links to technical documentation (progman,
white paper, etc) when appropriate.

The reason for this tutorial is to get interested developers coding quickly.