[MRM-425 and MRM-426]

[MRM-425 and MRM-426]
- Added and modified code for handling snapshots (if the versions of a specific artifact snapshot are only timestamped versions, add a
generic snapshot which is pointing to the latest timestamp version) in DefaultRepositoryBrowsing and ProjectModelToDatabaseConsumer.
- Updated pom validations in ProjectModelToDatabaseConsumer - handling of timestamped versions were considered
- Added isUniqueSnapshot(..) and isGenericSnapshot(..) in VersionUtil
- Added new attribute 'modelVersion' in DependencyTreeTag to get the in-pom version. Did not use the version attribute so as to retain the
actual version being browsed. Also updated DependencyTree
- Updated the ff. pages for the version to be displayed: artifactInfo.jspf, showArtifact.jsp, dependencyTree.jsp and artifactDecorator.jsp
- Updated the version in SearchResultHit

git-svn-id: https://svn.apache.org/repos/asf/maven/archiva/trunk@558795 13f79535-47bb-0310-9956-ffa450edef68