[Swan-commit] Changes to ref refs/heads/master

[D. Hugh Redelmeier]

New commits:
commit e01b644c1cc518696512a26dd8288ea9d61e55ad
Author: D. Hugh Redelmeier <hugh at mimosa.com>
Date:   Wed Dec 5 11:24:59 2018 -0500

    clarify interface to several event-deletion functions
    
    Each deals with a pointer to a pointer to the event.
    
    If the pointer to the event is NULL, the function does nothing.  This
    is considered normal and boring: no logging is performed.  So callers
    need not check for this case.  This was true for some functions but
    not all functions and it was not documented
    
    The pointer to the event is set to NULL by the deletion routine.
    This eliminates a dangling pointer.  Previously this was usually true
    but not always and was not documented.
    
    If the event pointer is not NULL, it must point to a known event.
    On pain of assertion failure.
    
    Simplify callers by exploiting these interface changes.
    
    Simplify find_ifaces().
    
    Inline unlink_pluto_event().
    
    const added; spelling fixed.