Fix horizon config under Apache 2.4

Apache 2.4 now uses mod_authz_host for acces control. Horizon's
Apache config needs an update to allow access to its directory,
otherwise a 403 will be returned.
This change replaces a similar previous fixes done for Fedora 18
and Ubuntu 13.10, since this is an Apache version issue, not a
distro-specific one.

Change-Id: Iecc17600d8e1aae6a7b0929b1493d712c307616f
Closes-Bug: #1243075
Fix FROM_PACKAGE checks for novnc and spice

The logic for installing novnc and spice from packages is broken,
which makes it impossible to install from git, which makes bug
1248923 more serious.

Change-Id: I9ae722a5470a16555bca9018da342485f6d3e896
Related-Bug: 1248923
Merge "Fix horizon config under Apache 2.4"
Merge "Fix FROM_PACKAGE checks for novnc and spice"
Merge branch 'master' of github.com:openstack-dev/devstack