[ARIES-997] Support for the Aries Application header Application-ImportService

This solution adds a new "fake" resource to the LocalRepository for subsystems that are being installed which have an
Application-ImportService header. The fake resource has no requirements and only contains osgi.service capabilities
that can be used to satisfy the imported services specified by the Application-ImportService header. These capabilities
can then be used during resolution to help resolve any osgi.service requirements from content resources when provisioning
the ESA. A new internal resource type (org.apache.aries.subsystem.resource.synthesized) is used to indicate to the
ResourceInstaller to ignore the fake resources during installation.

git-svn-id: https://svn.apache.org/repos/asf/aries/trunk@1430023 13f79535-47bb-0310-9956-ffa450edef68