Bing Maps key changes.

 * New default Bing key (Basic / Public website).
 * Write a message to the console when this default key is used.
 * Add the ability to supply a new default Bing key (and eliminate the
message) by setting a property, in addition to optionally passing it to
the constructor as before.
Consistently call the key a key.
Explicit primitive and id pick results
Finished picking update
Make Cartesian3.fromArray and alias of unpack.
Make fromArray an alias of unpack for Cartesian2 and Cartesian4.
Tweaks and CHANGES.md
Merge pull request #1142 from AnalyticalGraphicsInc/missingTriangles

Missing Triangles
Fixed typo
Start of Context.endFrame
More Context.endFrame
Start of sampler uniform optimization
Finish sampler uniform optimization
Updated CHANGES.md
Fixed array/uniform mismatch
Optimize calls to uniform1f from the central body shader
Reduce string creation for shader keys.  Drops 0.10% from the profiler
Only merge uniform maps when needed
Updated CHANGES.md
Fixed JSHint