OSGi Compatibility Stuff

 - Misc: Added default bin/ directory as ignored (for eclipse users)
 - Added Maven config to generate a OSGi Compliant MANIFEST.MF automatically
 - Added a Bundlor template with some rules about package imports version
 - Refactory of the LazyNestedProperty util class, as it packages conflicts with
   vaadin predefined
   - In normal Flat ClassPath this causes no issues, but with OSGi it becomes
     a big problem beasuse the Import directives, that causes this class to
     not be acessible even existing in the own bundle. A workaround is extract
     this class and inject it as a fragment on com.vaadin.server bundle.
   - As this class uses this namespace mainly to use use some protected static
     util methods of Vaadin (i think), I've refactored it consume this methods
     using reflection.