Don't build ucl when building upx, Debian stretch has a recent enough
version. In fact, the last upstream version doesn't build with GCC in
Debian stretch (http://bugs.debian.org/811707)
By default, wget prints dots every 1k bytes. This can render a
lot of output for large files. We switch to the "mega" style, which
makes each dot represent 64k, thus reducing output by up to 64x.
We also force the use of dot display. By default, it uses "bar"
which attempts to use terminal formatting if possible. Since most
of this code executes in CI and terminal control characters can
interfere with logged output, we force the use of "dot." (Although
wget appears to automatically switch to dot in TC today. But
consistency is good.)
MozReview-Commit-ID: IpTWJdcauTV
