mod_sasl2_fast: Fix harmless off-by-one error (invalidates existing tokens!) Problem: This was causing the key to become "<token>--cur" instead of the expected "<token>-cur". As the same key was used by the code to both set and get, it still worked. Rationale for change: Although it worked, it's unintended, inconsistent and messy. It increases the chances of future bugs due to the unexpected format. Side-effects of change: Existing '--cur' entries will not be checked after this change, and therefore existing FAST clients will fail to authenticate until they attempt password auth and obtain a new FAST token. Existing '--cur' entries in storage will not be cleaned up by this commit, but this is considered a minor issue, and okay for the relatively few FAST deployments.

# Groupchat 1.0 usage statistics gathering

Groupchat 1.0 was probably the protocol that predated
[XEP-0045: Multi-User Chat] and there is still some compatibility that
lives on, in the XEP and in implementations.

This module tries to detect clients still using the GC 1.0 protocol and
what software they run, to determine if support can be removed. 

Since joins in the GC 1.0 protocol are highly ambiguous, some hits
reported will be because of desynchronized MUC clients

# Compatibility

Should work with Prosody 0.10.x and earlier.

It will not work with current trunk, since the MUC code has had major
changes.