Merge branch 'master' into 'master'

Tone down makebuildserver terminal spamming

The progress bar updating at each 1k chunk spams the terminal to such an
extent it stops responding to keypresses (at least with a fast
connection). It also seems extremely inefficient to be writing the file
in 1k chunks. This makes it 64k, which is more reasonable but quite
probably still too small.

See merge request !134