Flash Builder project cleanup
Added optimize option to tweak the packing strategy.

Can either optimize for speed (fewer atlases) or memory (smaller
atlases). Memory is the default. Closes #48.
BitmapData Quality Settings

Adds support for changing the StageQuality setting used to render the
BitmapData when generting textures.

The default setting is StageQuality.BEST, however BEST is a relative
term since newer versions of the Flash Player have given us HIGH_8x8,
HIGH_8X8_LINEAR, HIGH_16x16, and HIGH_16X16_LINEAR.

Regarding Issue #39
Add missing library refs to Flash Builder exporter project
Bump AIR version to 3.7 (swf v.20)
fix flump-test compile errors
Flash Builder project: target latest swf version
LibraryLoader: handle IO error failure
Added an option to generate mipmaps for textures.

It makes loading slower and there is a slight memory penalty, but textures that use a large variety
of scales look a hell of a lot better with mipmapping enabled. trilinear smoothing helps a lot too
but the end flump user can turn that on himself by traversing the loaded Movie's Image children
and changing the smoothing property.
Merge pull request #56 from roguenet/master

Added an option to enable generated mipmaps on texture load.
Support ATF atlases in the runtime.

A lot of context can be muddled through in the disucussion here:
https://github.com/threerings/flump/issues/53.

In order to use ATF atlases in your runtime:
 * Unzip your flump archive
 * Modify library.json (or .xml), add a property to the top level element: "textureFormat":"atf"
 * Replace all of the .png atlases in the archive with your .atf encoded atlases
 * Zip it all back up and it should be good to go.

Tested on Mac Destop (Adobe claims Mac and Windows desktops are the same. It does not mention
Linux) and iPad 2. Some notes for people that might want to dive down this path:
 * One of Adobe's docs currently claims that transparency is not supported in the block-based
   compression formats, but this is incorrect, it works just fine.
 * My flump project is unusual (comosed primarily of parts of photos that were originally JPEGs, but
   I was still unable to get the quality of ATF textures up high enough to be usable in the end
   product. This is a great shame because the loading time was definitely better, and the flump
   archive was up to 70% smaller, if I built for iOS only. Traditional flump projects (composed of
   vector art from Flash symbols) will probably be even harder to get looking good using ATF.
 ** To this end I tried both with and without the -c flag to png2atf. When not using the -c flag, I
   tried -q 0: this both looked worse and was larger than my .png flump comparison. I also fiddled
   a great deal with creating my own PVRTC files both via texturetool (from XCode) and with
   PVRTexTool and then converting them to ATFs. I was unable to get a texturetool PVR to convert
   via ATF, and the PVRTexTool output looked just as bad as what I got via png2atf. I suspect this
   is partly because ATF only seems to accept PVRs that are using 4bits per pixel, so right off
   the bat you're losing half of your color depth.
Move LibraryLoader to a builder pattern.

I made the old static methods deprecated and removed the new generateMipMaps parameter from them.
Presumably if anybody other than me is already using it, they're paying enough attention to adapt
to this change too.
Enable external frankenweenies.

There are two approaches in use here:
 * Several points in loading dispatch a signal:
 ** file loaded from the .zip that wasn't recognized
 ** the library mold was loaded
 ** a ATF atlas was loaded
 ** a PNG atlas was loaded

I didn't end up needing all of these: I have no immediate use for the library mold signal, but it
seems generally useful, and I don't know what someone would even do with the ATF data other than
create a texture with it, but it seemed sensible to include it for completion.

 * a SymbolCreator factory pattern for letting flump consumers create custom MovieCreators and
   ImageCreators, giving them complete control over the final class that ends up on screen.

With the combination of these two, I have alpha based hitTesting for Images in my project, with
minimal memory impact.

Example gist for alpha hit testing: https://gist.github.com/roguenet/5651658
Flump 1.1 release
prepare for 1.2 development
create a CHANGELOG file
Fixed placement of the mipmap option
Make URL loading ProgressEvents available.
Those events come during any kind of Zip load.
Revert "Those events come during any kind of Zip load."

This reverts commit ad77fe85c23985b13b7b840a91ea351c267e9402.

OK, that was a lie. As far as I can tell, there's no way to get progress info for a zip decoding
when you hand off bytes instead of a URL.