nodequeue 6.x-2.4

Changes since DRUPAL-6--2-3:

• feature #234004 by wulff and ezra-g: drag and drop node ordering
• bug #512086: Can't add nodes using autocomplete textbox, titles display as restricted when manipulating queue for own nodes by ezra-g
• tweak to feature #442320 by Scott Reynolds : Integratation with Solr
• bug #528598 by Rob Loach and bloggybusiness: Conditional in nodequeue_requirements needs more parens
• bug #486438 by TheOnlyHarry:foreach error when drawing empty queue
• feature #212510 by cyberswat, baldwinlouie:
  hooks for add/remove
• bug #540810 by jpmckinney and ezra-g: nodequeue_apachesolr_update_index fails if empty