updated readme
programs can be shared as links
ability to generate permalinks in web shell
updated readme: added examples of fractals
Merge branch 'master' of github.com:ngn/u into grunt-build
changed format of "run" links

Base64-encoding the links to avoid a bug in Firefox: it incorrectly
unescapes the content of document.location.hash

https://bugzilla.mozilla.org/show_bug.cgi?id=378962
The doctests get run properly
Merge branch 'master' of github.com:ngn/u into grunt-build