EBookSqlite: Improved performance and simplified code

After much discussion on sqlite-users mailing list, I found
the real, correct technique for querying our multi attribute
values on the auxiliary tables.

  o Removed the crack query optimizer

  o Added the index to aux_table.uid (this is important
    to optimize contact inserts, as we have to delete
    all aux_table.uid entries in the case of a replace).

  o Drop the LEFT JOIN statements in favor of

    JOIN 'folder_id_email_list' AS 'email_list' ON +email_list.uid = summary.uid

    This does not create exponentially huge data sets because of the ON
    statement, the '+' ensures that email_list.uid is ineligable for
    indexing, since we want to use email_list.value indexes later on.
test-client-custom-summary: Added test for the 'x-evolution-any-field' NULL special case

x-evolution-any-field with a NULL value (or byte) means 'get all contacts'.
test-client-cursor-operations.c: Removed bogus test for invalid sexp

No search expression is invalid anymore.