Changes keyframe model (see upgrading.md).  v.0.8.4.  Fixes issue #11.

Squashed commit of the following:

commit 1010434f7be03ba533ce4c46ca498aa34fe6317c
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sat May 26 14:56:50 2012 -0700

    Fixed a wait bug where easings weren't copied.

commit a7c5758a706155d96d6f2285223dd967a58add4c
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sat May 26 14:30:15 2012 -0700

    Adds upgrade instructions for wait().

commit 08982645621fdda7c222d78271b73b968f30f993
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sat May 26 14:25:33 2012 -0700

    Rebuilds 0.8.4.

commit bf48e3707fbb295049236dc998f1c6884f5eabc8
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sat May 26 14:23:13 2012 -0700

    Updates the way removeKeyframe and wait work, updates some tests.

commit e828874d739e3b3875d645c1dc8d20efc2ab439b
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sat May 26 14:11:47 2012 -0700

    Updates a test.

commit f76a5379f0ca3619ec06dc2be2740fe95cd24b42
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sat May 26 14:00:44 2012 -0700

    Fixed munging bug in the bubbles demo.

commit 7871f733312e20529af2269972ef22a3088a73c0
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Fri May 25 21:58:44 2012 -0700

    Tweaked wait some more.

commit 848528fa83237cac6e6f549ad242b9ec4179262c
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Fri May 25 21:34:47 2012 -0700

    Reworks wait.

commit 7034a22e976ef71bbe114e929a66db77519f5567
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Fri May 25 21:25:09 2012 -0700

    Adds a failing test.

commit 3aa1701e757ee8ffa340f1db29db60746321bc20
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Fri May 25 21:03:27 2012 -0700

    Added annotations for getLatestProperties.

commit 9724b3e78547794f663455bdb8fc1ff82a379b6f
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Fri May 25 20:57:07 2012 -0700

    Added upgrade instructions for 0.8.4.

commit 688a8f6dd2ae4de57c817e21c6205f1015acc09a
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Thu May 24 23:05:50 2012 -0700

    Updated the pie demo for the new keyframe model.

commit ecc74e3c4f786e03452da027e0806dbc33ff5d58
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Thu May 24 23:00:49 2012 -0700

    Updated bargraph demo for new keyframe model.

commit 3c6cc25b9fe45b5793b1729e4e047873dd6964a4
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Thu May 24 22:52:38 2012 -0700

    More getLatestPropeties tweaking.

commit ca2362d6ba4081ed3d5fb2dcd51f90c10c0480d2
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Thu May 24 22:23:25 2012 -0700

    Tweaked getLatestPropeties and a test.

commit 18eab4f3b9a7477bc20893985e045163f80b4341
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Thu May 24 19:12:59 2012 -0700

    Tweaks getLatestPropeties.

commit 6b35a7d87bd469529c6bc5c7597989144fe2b6c5
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Wed May 23 22:25:08 2012 -0700

    Created a possibly useless abstraction.

commit 2bfb3f7b3c20556f5b0185a7382a725aac074016
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Tue May 22 23:04:39 2012 -0700

    Adds a failing test assert.

commit 64fc723c5852596e8f7e1415db378fa4b129acf9
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Tue May 22 22:57:06 2012 -0700

    Fixes a failing test.

commit 3124b578c4a3d4ec044e44e602b53b3a92846eae
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Tue May 22 22:54:13 2012 -0700

    Adds a failing test.

commit d2eab1f5b6877987bdaf2924f953b487edcfe614
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Tue May 22 22:43:33 2012 -0700

    Rebuilds 0.8.4.

commit 858d7cc5ab8aec9861530de6b1ba395100edd29b
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Tue May 22 22:39:34 2012 -0700

    Fixed a failing keyframes test.

commit 0c29eaabd726cdfde90f69d8951fcb65ce62015b
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Tue May 22 20:45:41 2012 -0700

    Adds a failing test.

commit e60ad40125412a118561b06d47a9c5ee40809a91
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Tue May 22 20:34:41 2012 -0700

    Removed fillInMissionProperties.