lp1102300 auto-register .md5 variants of methods

lp1102300 auto-register .md5 variants of methods

This only handles the Perl side at the moment, and probably very naively (for
example, opensrf.system.echo.atomic.md5 and opensrf.system.echo.md5 do not
return the same MD5's for the same input--though that's not important for my
purposes).  If someone wants to clean it up and implement the C side of it as
well, that would be awesome.

One downside is that at times, we will be doubling the amount of work done on
the server (whenever we call an .md5 method and then decide to call the real
thing), however, in the context of Evergreen, most servers that I'm aware of are
hardly ever under load, and instead it's network, data-size, and client issues
that cause poor responsiveness, so I think it's more important to send less data
over the wire when we can, and this will help with that.

Example:

srfsh# request open-ils.actor opensrf.system.echo.md5 "test"

Received Data: "303b5c8988601647873b4ffd247d83cb"

Signed-off-by: Jason Etheridge <jason@esilibrary.com>