experimental: optionally shorten the tab labels in the communications
              floater through "&-IMShortTab", and exclude from
              shortening through "&-IMLongTab"

WARNING: this also shortens log file names --- if there was a way to
         shorten the tab labels after the floater has been created,
         this could be avoided
xantispam: show the IM counter button that comes up when the
           communications floter is closed only if wanted, using
           "&-IMNoCountingButton" and "&-IMCountingButton" rules
experimental: "&-IMLongTab" and "&-IMShortTab" have become an
              internally merged request to avoid multiple calls of
              xantispam_check() to answer a single question and to
              implement some logic to reach a decision gracefully.

WARNING: still messes with log file names
Merge branch 'master' into experimental

: get the fix for broken log file names in
Merge branch 'master' into experimental

: disable "&-IMLogDistinct"
Merge from https://github.com/Lirusaito/SingularityViewer.git into
experimental
Merge branch 'master' into experimental

: get fix for history in local chat
removed obsolete debug output
experimental: "&-IMLongTab" and "&-IMShortTab" now work without
              messing with the log file names

This features is no longer experimental.
xantispam: fixed logic determining wether to use a long or a short tab
           for an IM session in the communications floater
xantispam: reset max tab width to be able to display long tabs after
           displaying a short tab
xantispam: leaving addFloater() untouched, using addFloaterSmallTab()
           instead
xantispam: added AntiSpamXtendedMaxTabLength debug setting to specify
	   the maximum tab length for when the &-IMShortTab rule is
	   applied
xantispam: increased the default for the
	   AntiSpamXtendedMaxCallsPer10Sec debug setting from 100 to
	   300