Merge 0.11->trunk

mod_muc_mam: Remove spoofed archive IDs before archiving, fix #1552 The stanza-id added during archiving looks exactly like what should be stripped, so the stripping must happen before archiving. Getting priorities right is hard! Also no test coverage yet.

mod_csi_simple: Report whatever's not a stirng and not a stanza This is either dead code or actually a type error, but catching that should be the responsibility of the session.send function. This type check is left since everything after it assumes a stanza object. These last few commits aren't meant to change any behavior and it did mark things not stanzas as important, but those would have been mostly raw strings which are now specially handled.

mod_csi_simple: Report whitespace keepalives Single space character is sent by mod_c2s when a session has been silent for some time. This should account for the vast majority of raw strings passing through here. If this is not the case then having stats to say otherwise will be interesting.

mod_csi_simple: Identify raw string data in logging and stats

mod_csi_simple: Collect stats on flush reasons

mod_csi_simple: Record stats of how long buffers are held Telnet command `stats:show("buffer_hold"):histogram()` looks nice!

mod_csi_simple: Change debug message of client-triggered flush for coherence It now matches other the other source of flush reason logging.

mod_csi_simple: Reset queue counter to zero when enabling For symmetry.

mod_csi_simple: Forget queue counter when disabling optimizations Otherwise it might not start from zero when enabled again.