Use timestamp format for manual away, not restore

Apply the timestamp formatting to manual /away commands, too.  This
offers consistency between the auto-away settings and manual away.

Add skipFormatting flag to handleAway/issueAway commands to skip
applying timestamp formatting.  This avoids re-processing timestamp
formatting when restarting the core, leaving any '%%' as '%%'.  The
message should already be processed once stored.

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