Add the es5-shim library to the common bag.

Features of the es5 spec are in use in various places across Tiddlyspace. This library provides the functionality for browsers that do not support it natively.

For example it'll be used here:
https://github.com/TiddlySpace/tiddlyspacesockets/commit/efcf2e19aefdde2b5447fd9170cbc4b7adef2234#commitcomment-2452294