Fix wrong guava from transitive dependency

- guava 11 was being pulled in by org.reflections:reflections, in core
Fix BrooklynNode filename in download urls
Deprecated brooklyn.util.internal.duplicates.ExecUtils
Fix sandbox compilation errors
Merge pull request #944 from aledsage/fix/various-20130923

Minor fixes (wrong guava, and BrooklynNode filename)