Compatibility with guava 21

- Objects.ToStringHelper has been moved to MoreObjects. We now
reimplement the functionality in order to be compatible with both guava
15 and guava 21
- com.google.common.base.Predicate now extends
java.util.Function.Predicate. As a result static imports of "and" and
"or" from Predicates are shadowed by java.util.function.Predicate
variants, preventing the statics from being called unless explicitely
qualified.

Change-Id: Ie33d5eedd9e1a6dbea8f4af2db9aa36ec8567cf5
49 files changed