Removed some unused classes.
Mentioned Zsolt's fixes for FreeBSD.
Minor javadoc edits.
Changed GradlePomModuleDescriptorParser to treat a timestamp version in the pom as a -SNAPSHOT version in the meta-data.

- Removed DescriptorParseContext.getCurrentRevisionId() as it is no longer required.
Extracted ComponentMetaData, ComponentArtifactMetaData and ComponentArtifactIdentifier out of the corresponding ModuleVersion types.

- Changed LocalArtifactMetaData so that it is-a ComponentArtifactMetaData.
- Not used anywhere else yet.
Removed some unused classes.
Removed some unused constructors.
Hoisted up getName()  to ComponentArtifactMetaData, for backwards compatibility.
Use ComponentArtifactIdentifier instead of ModuleVersionArtifactIdentifeir in a few places.