Revert "- yWeb: disable threading; there's something to fix"

This reverts commit 91d0f106b13bb74d1fba65de60290e4ea4e6017e.
nhttpd: disable range handling for cached content
src/zapit/zapitclient: add a mutex to protect against concurrent calls from nhttpd threads

Signed-off-by: Jacek Jendrzej <crashdvb@googlemail.com>
add localization tag for time elapsed/remaining
Merge remote-tracking branch 'cool-cst-next/cst-next'

Conflicts:
	src/zapit/lib/zapitclient.cpp