Continued constraint propagation issues with Proxy ITs

Still, I'm seeing issues with the T*ProxyIT classes on the methods that have to do with constraints.

testBatchWriter() and testConditionalWriter() have both failed recently (thanks for romil.choksi for letting me know about 'em)

We can try offline'ing and then online'ing the tables after changing the constraints to force the server to reload the configuration. Otherwise, I'm going to be in favor of just disabling these tests as they're a pain in my rear.