R1:77a5a3ab0088

Add a basic Conduit log view

Summary:
The conduit access to Differential kind of sucks and we want to break
back-compat in order to fix it (see D1114).

To make it easier to pull this off, I want to build out the Conduit logging a
bit so administrators can identify which users are making deprecated calls.

We should probably build a little more infrastructure around this too (API
versions?), but this is at least a reasonable step forward which gives us more
insight into the use of Conduit and more tools…