Hardcoded URLs / Missing Parent clauses prevent mvn deploy from working

There are few problems in the l2switch project which are preventing the deployment of bundles (via the mvn deploy command) from working correctly. These problems arise in a non-ODL environment that does not use jenkins to deploy their artifacts.

Problems:

1) In the distribution management section, we are hardcoding the URLs to the repositories where we should be uploading the artifacts. However this prevents users from building and uploading their artifacts to their own repositories. Thus using a variable in the distributionManagement section only will allow this to work for everyone.

2) The "aggregator" pom.xml pattern that has emerged does not derive from a common parent and thus does not inherit a distributionManagement section. Without a distributionManagement section we can not upload the artifacts to a repository (unless you use a third-party tool such as jenkins or something). To fix this we should have all pom's inherit from a common parent which defines a single distributionManagement section.

To validate that these fixes do not break anything, do a 'rm -rf ~/.m2/repository/org/opendaylight' and then rebuild the project. Make sure everything compiles.