Since we pass a method: 'foo' to every one of these
config-tool/pkg-config dependencies, we do not ever need to check which
type_name it has; change these to asserts instead.
In the process, we discover a bug! We kept checking for type
'configtool' instead of 'config-tool', so these tests all
short-circuited and checked nothing. Once moved to an assert, the
asserts failed.
Add a new lookup for a known system dependency and make it assert that
too.