[racket] WeScheme developers heads up: build process changed

Hi everyone,

[Ignore if you don't do WeScheme development]

For people developing on WeScheme: the build process for WeScheme is
slightly changed in my master branch.

*  build-console-and-editor.sh has been deprecated in favor of
build-console-and-editor.rkt.

*  I've updated the dependency of Google Closure Compiler to use the
latest release, and have it automatically install it under
war-src/closure.