Install agent packages when running agents like DHCP or L3

This is because these agents rely on quantum agent packages as
much as the L2 agent.

Fixes bug #1190050

Change-Id: I8b0c5667f86b22e3727a316f7bb0500d0d0ba637
Merge "Install agent packages when running agents like DHCP or L3"
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp