Fix some checkstyle exceptions, and remove entries from the checkstyle suppressions file.

Obsolete one class where we can use Guava instead.
Fix https://github.com/julianhyde/optiq/issues/138, "SqlDataTypeSpec.clone handles collection types wrong".
Fix https://github.com/julianhyde/optiq/issues/135, "Add a PARSE_TREE hook point with SqlNode parameter".
Upgrade to guava-15.0 (guava-14.0.1 still allowed) and sqlline-1.1.7.