sqlite_sequence is not considered a systems table

When used with a SQLite database, the table sqlite_sequence is returned by QSqlDatabase::tables(QSql::Tables) and not by QSqlDatabase::tables(Sql::SystemTables). Lukas convinced me that this is in line with sqlite (see our discussion at http://qt-project.org/forums/viewthread/23147). However, it is still an unexpected behaviour.

I suggest to include a hint in the documentation (i.e., in file http://qt.gitorious.org/qt/qt/blobs/4.8/src/sql/kernel/qsql.qdoc, line 99): "\value Tables All the tables visible to the user. (Note: this includes sqlite_sequence as sqlite considers it a regular table)"