Add a debug page exposing the bugs that happen when switching layers with different zoom levels.
Fix for https://github.com/CloudMade/Leaflet/pull/623

There seems to be a timing bug though.
Added a bunch of tests and fixed some bugs those exposed.
Also don't try to automatically adjust zoom. Leave that to the
layer control for now and wait for a setBaseLayer / switchLayer
or something instead.
Update src/layer/tile/TileLayer.js

this should solve first problem in #1089 (http://jsfiddle.net/Q3SFZ/1/)
Merge pull request #1166 from OriginalSin/patch-1

Solves issue #1089
Return created HTML element in Control.Layers._addItem

Goal is to make easier and DRYer to customize layer HTML item
when extending Control.Layers class
Merge pull request #1167 from yohanboniface/layers_control

Return created HTML element in Control.Layers._addItem
fix error in initializing map on hidden iframe in Firefox
Merge pull request #1171 from dreamfall/patch-1

Fix error in initializing map in hidden iframe in Firefox
Update the Layers control when layers are added or removed
Merge pull request #1169 from tomhughes/layers

Update the Layers control when layers are added or removed
Wrap the last test in a map.whenReady to ensure the map has finished loading
before removeLayer is called.
Stupid typo
Merge pull request #1159 from moonlite/master

First stab at a fix for Issue 623
fix code style issues #1159, update build
Re-order zoom end so we completely stop the zoom before getting people to redraw. Otherwise firefox will animate the canvas redrawing which is totally weird. Fixes #1187
Merge pull request #1188 from danzel/zoom-fixes

Fix firefox canvas zooming
Always set canvas alpha. Fixes #1186
Merge pull request #1189 from danzel/canvas-fixes

Always set canvas alpha. Fixes #1186
fix for issue #892 , second time around.