Updated databases/sqlite3 to 3.6.4

* Add option support for LIMIT and ORDER BY clauses on DELETE and UPDATE
  statements. Only works if SQLite is compiled with
  SQLITE_ENABLE_UPDATE_DELETE_LIMIT.
* Added the sqlite3_stmt_status() interface for performance monitoring.
* Add the INDEXED BY clause.
* The LOCKING_STYLE extension is now enabled by default on Mac OS-X
* Added the TRUNCATE option to PRAGMA journal_mode
* Performance enhancements to tree balancing logic in the B-Tree layer.
* Added the source code and documentation for the genfkey program for
  automatically generating triggers to enforce foreign key constraints.
* Added the SQLITE_OMIT_TRUNCATE_OPTIMIZATION compile-time option.
* The SQL language documentation is converted to use syntax diagrams
  instead of BNF.
* Other minor bug fixes

(martti)