improve view management: - we can pass a negative view index, in this case we count from the end of the list of view - before creating/changing the view representation, we remove the previous one and reinitialize the node visibility - each time we save a view, it creates a new one at the end of the list - "restore" view loads the last view of the list

<?xml version="1.0" encoding="UTF-8"?>
<metadata>
  <groupId>org.opencoweb</groupId>
  <artifactId>coweb-java</artifactId>
  <versioning>
    <versions>
      <version>1.0.1-SNAPSHOT</version>
    </versions>
    <lastUpdated>20131014145404</lastUpdated>
  </versioning>
</metadata>