Use ModuleInfo, not CommandInfo, where feasible

There is very little reason to limit ourselves to commands only, even
though in practice right now Ops are always commands. The API should
keep the door open for other possibilities in the future, though.
DefaultOpMatcherService: fix bug in matches output
ProjectorTest: remove erroneous TODO

The method in question is "initImg" not "testSum"...
MedianRealType: name is "median" not "sum"

Sorry, Jenkins!
Add missing Mean interface

Sorry again, Jenkins!