API to find autorecords based on multiple column values

[wouter bolsterlee]

In addition to AnewtAutoRecord::db_find_{one,all}_by_column() I'd also like ::db_find_{one,all}_by_columns() that will find records based on mutiple column values (using AND in the SQL WHERE clause).

I'm working on this, but need to cleanup my patch before I submit.

[wouter bolsterlee (wbolster)]

Finally got around to cleaning things up:

 1749 Wouter Bolsterlee 2010-02-16
      [autorecord] Implement ::db_find_{one,all}_by_columns()

      These methods takes an associative array of column names and
      values and returns the records that match all values, using
      AND in the WHERE clause.

      This is a generalization of the existing functionality
      offered by the ::db_find_{one,all}_by_column methods, but
      extended to support multiple columns instead of just one.
      The _by_column() methods now invoke their _by_columns()
      counterparts instead of duplicating the SQL building logic.

      Also extended the unit tests to test the new functionality.

      Fixes bug #503551.