Use chunking to prevent excessive upload sizes.
(cherry picked from commit 4321c01d3eab1a5216a4f556cc8447de212836ef)
Fixed small mistake in swfupload.swf.
(cherry picked from commit ae7d5aeab6073db2bb7a3fd2111faf2debe36b11)
Another small improvement to swfupload.swf, fixing upload progress indication.
(cherry picked from commit 419d7dc69d9f98bd5f3afee6bf5f8c72a8cf6cdf)