Hopefully improve code comments for issue #3616.
Hopefully improve code comments for issue #3616.

This commit also contains other changes in order to conform the code to
the Redis core style, specifically 80 chars max per line, smart
conditionals in the same line:

    if (that) do_this();

JackieXie168/redis,JackieXie168/redis,JackieXie168/redis,JackieXie168/redis