Improve Karaf3 features before Karaf4 migration

Improve Karaf3 features before Karaf4 migration

+ Feature artifacts inherit from odlparent:features-parent now.
*+ src/main/features/ instead of src/main/resources/.
*+ {{VERSION}} instead of version properties.
*+ No explifit versions for feature dependencies.
+ Use artifact poms: upstream, distribution and all.
*+ Only upstream artifact pom has version properties.
*+ The version properties have simpler names.
+ Removed superfluous maven-bundle-plugin configuration from Version pom.
+ TODOs to rename feature artifactIds.
- No TODOs to use org.opendaylight.integration.distribution
+ General comment line improvements.
+ Added missing licences.
+ Update copyright years on files where edits were significant.
+ Each POM uses parent from Odlparent (instead inheriting from aggregators).
+ Add log.txt to .gitignore

Change-Id: I8d4ce2ba40674138cdefdedc3bc81f3bce907ac7
Signed-off-by: Vratko Polak <vratko.polak@gmail.com>