Fast but no feedback

mini-icons downloads get batched over a single connection thru the use
of wget -i.
Drawback is, since the script code delegates download control, there's
no longer per-icon percentage update, hence no user feedback.
Recovered icons download progress feedback

By parsing wget output on the fly

$POL_WGET --quiet-no is a bit unfortunate, improvements welcome.
Merge branch 'dev-fastlistupdate'

Important speedup of icons download by reusing a single HTTP connection