Merge branch 'TimePath/strfree' into 'master'

Add strfree to reduce explicit use of strunzone/string_null

See merge request xonotic/xonotic-data.pk3dir!552

diff --cc qcsrc/client/bgmscript.qc
Simple merge

diff --cc qcsrc/common/triggers/func/pointparticles.qc
Simple merge

diff --cc qcsrc/lib/net.qh
Simple merge

diff --cc qcsrc/lib/replicate.qh
Simple merge

diff --cc qcsrc/menu/xonotic/serverlist.qc
Simple merge