Apparently the system.Versions table was removed as part of
CASSANDRA-4018. cqlsh in 1.2 should use system.local preferentially, and fall back on system.Versions to keep backwards compatibility with older c*.
Also changed in 4018: all the system.schema_* CFs now use columns named "keyspace_name", "columnfamily_name", and "column_name" instead of "keyspace", "columnfamily", and "column".
While we're at it, let's update the cql3 table structure parsing and the DESCRIBE command for the recent Cassandra changes too.