Test for an MFHD warning in 14-OpenILS-Utils.t

Test for an MFHD warning in 14-OpenILS-Utils.t

Specifically "Cannot compress without pattern data, returning original holdings"

I also added Test::Warn to Makefile.install for Debian and Fedora.

--
Bill moved the @comp_holdings variable declaration outside of the
warning_like block to avoid a new warning:

Name "main::comp_holdings" used only once: possible typo at
t/14-OpenILS-Utils.t line 42.
---

Signed-off-by: Jason Etheridge <jason@esilibrary.com>
Signed-off-by: Bill Erickson <berick@esilibrary.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>