Fix Drawer event emission

Drawer tries to emit events on the parent Viewer object but doesn't have
a reference to it.  Add a reference when constructing the Drawer.
test: Drop workaround for broken Drawer event emission
Merge pull request #94 from bgilbert/drawer-events

Fix Drawer event emission
Merge pull request #46 from houseofyin/issue37-navigator

Issue37 navigator
Fixed typos in comments
Updated changelog
Changelog updates for #46
Added a demo of the basic default viewer
Updated changelog for #48
Now trying standard path first in createAjaxRequest

As suggested by @cskwg in #98
Added test for makeAjaxRequest
Minor fixes to basic demo
Paranoid requestAnimationFrame for antique Firefox

Very old versions of Firefox - e.g. Firefox 7 - have
window.requestAnimationFrame but not cancelAnimationFrame. This is a
very old release so the easiest fix is simply to check for both of the
functions which we intend to call and fall back on traditional behaviour
if both aren't present.
Merge pull request #103 from acdha/paranoid-requestanimationframe-polyfill

Paranoid requestAnimationFrame for antique Firefox
Our requestAnimationFrame no longer changes the global window object
Tests for requestAnimationFrame and cancelAnimationFrame
Whitespace nits
Merge pull request #104 from openseadragon/raf

Our requestAnimationFrame no longer changes the global window object
Working on follow-up on the initial pull request.  Changing the default navigator display property, and starting work on the docs
Merge branch 'master' of github.com:openseadragon/openseadragon into issue37-navigator