Makefile prerequisite installer should install database server prerequisites too

[Dan Scott]

* Evergreen 2.6+

Related to bug 1147028, but just a small part of it. The README currently states under "Setting up the PostgreSQL server":

"""
(Ubuntu Precise).

apt-get install gcc libxml-libxml-perl libxml-libxslt-perl libbusiness-isbn-perl
apt-get install libjson-xs-perl liblibrary-callnumber-lc-perl libmarc-record-perl
apt-get install libmarc-xml-perl libuuid-tiny-perl
cpan Rose::URI
"""

... and similar for other distros. Given that we have a Makefile for prerequisite installs, and that there is a target for installing the database server, it's kind of silly to require users to manually install those packages.

Instead, we'll define a variable listing the database server packages, then pull that into both the core prerequisites and the database server prerequisites. Note that some of the packages might already be installed as part of OpenSRF; that's fine, as they will just get skipped in the Evergreen core but we need them on the database server (where OpenSRF itself may not be installed).

The motivation for this bug is that during the course of a database server upgrade, the special packages were missed because they were a manual step in the README... The result was that we were unable to edit, create, or delete call numbers because Library::CallNumber::LC was missing on the database server. And while one could say "Ah, you should have read the README", we could make the lives of poor sysadmins that much easier by automating as much as possible.

[Dan Scott (denials)]

See http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/dbs/lp1362210_db_server_packages for a branch that tries to address this across distros (and has the benefit of slimming down the README too).

[Ben Shum (bshum)]

Merging this for 2.7 to make installation easier. Thanks Dan!