various: Use 0.12+ API for serving files from the file system over HTTP
Using mod_http_files this way is deprecated. Having the base behavior in
a separate module makes it easier to have a specialized module with
coherent behavior that does not do things when not explicitly enabled.
This module helps reduces power usage of inactive mobile clients while
another client is actively used. E.g. in the case of chatting on a
desktop computer, instantly pushing messages to a phone in someones
pocket is not the best use of radio time.
Works with [mod_csi_simple][doc:modules:mod_csi_simple] which is
included with Prosody since 0.11