Prefer local features

Prefer local features

PopulateLocalRepoMojo should prefer features from the local repository
(the Karaf installation repository, typically) to those in the system
repositories: this allows features to be patched, and the patches
taken into account when resolving dependencies.

(Adding the local repository to Aether’s repositories doesn’t have the
intended effect, because the feature dependencies have generally
already been resolved, and are resolved again from the cache when
PopulateLocalRepoMojo runs.)

JIRA: ODLPARENT-189
Change-Id: I232115e0fcdef1ae17c22a17028021f825573e31
Signed-off-by: Stephen Kitt <skitt@redhat.com>
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>