Deprecate sql_* for database_*

Upstream change d5ae9ea70ed878e08e1d195f34c1989ecdd0b74f deprecated
default sql_* options for a new [database] section.

This deprecates the sql_ options and moves the new options into
the [database] sub-section of the config file.  If sql_* values are
given, they should be used but give a deprecation warning.

Change-Id: I05db83ace63399c0b2ebd63f74f5dc76ff5d3e9a