Followup r90429:
* Reverted the public -> protected changes from r90429, except for doQuery() after a review of usage:
** resultObject() is used by lots of things in core and extensions.
** makeSelectOptions() is used by SMW, and if that's going to be public, the other two probably should be too, for consistency.
** doQuery() was used by several things, but mostly by mistake. It's been marked private since r21359 which is before almost all of them. I updated the callers to use query().
* Added "protected" to doQuery() declarations in other database classes.