SQL_BIG_RESULT used": now BIT_AND() always returns 18446744073709551615
if no rows were found.
This patch also fixes bug #1972: "BIT_AND() and BIT_OR() still return
a *signed* 64bit value"
Added ALL as parameter option for all group functions.
Make join handling uniform. This allows us to use ',', JOIN and INNER JOIN the same way.
Sort NULL last if DESC is used (ANSI SQL 99 requirement)
MIN(key_column) could in some cases return NULL on a column with NULL and other values.
MIN(key_column) and MAX(key_column) could in some cases return wrong values when used in OUTER JOIN.
