PHOENIX-1250 Remove use of Closeables.closeQuietly

Remove the use of Guava's Closeables.closeQuietly to allow using
Phoenix within a client-side application that has a more recent
version of Guava. After this commit, Phoenix can be built against
Guava 18.0 (although full integration tests will not work because
HBase/Hadoop still rely on an older version of Guava internally).