Add CONF_METAPKGS to select cart metapackage deps

Added new configuration variable, CONF_METAPKGS, which allows users to
selectively install `optional`, `recommended` or `none` cartridge
dependency metapackages.

Default is `recommended`

`parse_cartridges` is updated to only install the cartridge metapackages
for the selected cartridges

Squashed commit:

Rewrite parse_cartridges metapkg logic

Updated `parse_cartridges` metapkg logic to rely on the resolved value
of `pkgs`

Rewrote `metapkgs_optional` and `metapkgs_recommended` to not use `grep`
Merge pull request #310 from dobbymoodge/conf_metapkgs

Add CONF_METAPKGS to select cart metapackage deps
Conditionally loop over metapkgs

Added check to prevent looping over the metapkgs in `parse_cartridges`
when `CONF_METAPKGS=none`
Merge pull request #312 from dobbymoodge/conf_metapkgs

Conditionally loop over metapkgs
installer: de-deplux activemq network connectors

Bug 1070747 - de-duplicate connectors on Network of ActiveMQ Brokers
https://bugzilla.redhat.com/show_bug.cgi?id=1070747

From docs bug:
https://bugzilla.redhat.com/show_bug.cgi?id=1066729
Procedure 7.20. To Configure a Network of ActiveMQ Brokers
Links to a broker configuration which uses duplex
NetworkConnectors. These duplex network connectors need only be
configured from the initiating broker, not on both sides of the
connection.
Merge pull request #314 from sosiouxme/duplex-ha-activemq-enterprise-2.1

installer: de-deplux activemq network connectors