Taxonomy db table names have changed to begin with 'taxonomy_'

Attached patch.

Test function:

function example_taxonomy_db_tables() {
  $result = db_query("SELECT * FROM {term_data}");
  $result = db_query("SELECT * FROM {term_hierarchy}");
  $result = db_query("SELECT * FROM {term_node}");
  $result = db_query("SELECT * FROM {term_relation}");
  $result = db_query("SELECT * FROM {vocabulary}");
  $result = db_query("SELECT * FROM {vocabulary_node_types}");
}