No protos in the headers yet and no docs.

format some function references properly

version

with it (knowing it won't be larger than what fits in an int)

content-length when doing multipart posts

sizes if desired

CURLOPT_POSTFIELDSIZE option to allow really big HTTP POSTs.

return their values

make the progress meter more accurate for large files. Also made the sprintf
usage in that function avoid floating point.

argument passing and try to convert to double only when providing data to the
external world.