ES6 has Array.prototype.find (conflicts with HTML._.fn.find for element lists)

See: http://people.mozilla.org/~jorendorff/es6-draft.html#sec-15.4.3.23

This means before we go 1.0, we'll have to s/find/query, unless someone has a better name idea.  HTML.query() is a wee bit less readable and terse, but it is a much more specific/accurate term, which should prevent further conflicts.

It also means a deprecation round, so there will definitely be a 0.10.x branch.
