- move LIMIT/OFFSET rendering to be as bind parameters, for all backends

- move LIMIT/OFFSET rendering to be as bind parameters, for all backends
which support it.  This includes SQLite, MySQL, Postgresql, Firebird,
Oracle (already used binds with ROW NUMBER OVER), MSSQL (when ROW NUMBER
is used, not TOP).   Not included are Informix, Sybase, MaxDB, Access
[ticket:805]
- LIMIT/OFFSET parameters need to stay as literals within SQL
constructs.  This because they may not be renderable as binds on
some backends.