New materials on ES4 available

[Lars Hansen]

The document on compatibility between ES3 and ES4 has been updated
significantly:
http://www.ecmascript.org/es4/spec/incompatibilities-rev1.pdf 

I have written a tutorial called "Evolutionary programming and gradual
typing in ECMAScript 4":
http://www.ecmascript.org/es4/spec/evolutionary-programming-tutorial.pdf

Both are based on the 23 October "Language Overview" white paper, with
later adjustments that are currently only recorded in the Trac at
http://bugs.ecmascript.org.  (The Language Overview needs to be revised
to reflect those adjustments.  One of these days...)

--lars