Adds user-facing alerts for invalid easing input.

Squashed commit of the following:

commit 01c34f9d65e07db97e962b53a45f9267f4cdc048
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sun May 26 16:07:08 2013 -0700

    Rebuilds binaries.

commit 9c81c757339e1aa2ff8b919ce480383ca17fe37d
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sun May 26 16:05:00 2013 -0700

    Adds a note.

commit 5d600830b1dc1bdd54d25118ddcb1563931affc0
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sun May 26 12:38:56 2013 -0700

    Fixes some responsiveness issues with EaseFieldViews.

commit 85dfe1f2a53d13ffb220979571d88c1ad1837cbf
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sun May 26 12:31:37 2013 -0700

    Shows an error alert when invalid JS is input for easing.

commit 3f3b33e835358e1bd86309f063dde823f138f1a4
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sun May 26 12:23:14 2013 -0700

    Adds alert View.

commit 32c0a078093ef4880a73e69b910a10438985e29f
Author: Jeremy Kahn <jeremyckahn@gmail.com>
Date:   Sun May 26 12:04:18 2013 -0700

    Adds initial styles for alerts.