curl: progress bar refresh, get width using ioctl()

Get screen width from the environment variable COLUMNS first, if set. If
not, use ioctl(). If nether works, assume 79.

Closes #2242

The "refresh" is for the -# output when no total transfer size is
known. It will now only use a single updated line even for this case:

The "-=O=-" ship moves when data is transferred. The four flying
"hashes" move (on a sine wave) on each refresh, independent of data.