Generate buildfile from Eclipse workspace

Creates a buildfile from the current Eclipse workspace

• detecting eclipse project (which may be anywhere in a subdir)
• project-names from eclipse .project-files override directory names
• uses default eclipse values ('src','bin') for layout[:source,:target]
• get the project version from MANIFEST.MF
• adds dependencies between project
• adds hints for all plugin
• skips fragments (would need buildr4osgi to handle them correctly)
  Patch will be attached soon.