Merge branch 'Mario/intrusive' into 'master'

Merge branch Mario/intrusive (XL merge request)

Ports a few more FOREACH_ENTITY_* loops to the new intrusive lists system, further restoring the performance lost by the pure entities.

See merge request !361

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

diff --cc qcsrc/common/mutators/mutator/itemstime/itemstime.qc
Simple merge

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

diff --cc qcsrc/server/g_world.qc
Simple merge