Experimental Dropbox release (Build 1.3.16)

Get an invite here http://db.tt/5a9mHMz

-Support AVCHD (Note: most of these devices need to be plugged in using PC mode for this to work.)

-Fix Finder crash in 10.7.3

-Don't autoupdate while photo import is happening

-Better UI responsiveness while Importing

-On install wait for file transfers to finish before restarting Windows Explorer.

-Fix missing msvcr71.dll issue

-Offer to install Autoplay proxy on first restart after autoupdate.

-Other small fixes