Untangle a few cyclic dependencies

src/refit/agreement/pbft/REFITPBFT.java

src/refit/agreement/pbft/REFITPBFTTransition.java

src/refit/agreement/pbft/REFITPBFTTransitionCertificate.java

src/refit/agreement/steward/REFITSteward.java

src/refit/agreement/steward/REFITStewardCertificate.java

src/refit/agreement/weave/REFITWeave.java

src/refit/application/log/REFITLogClient.java

src/refit/application/probe/REFITProbeClient.java

src/refit/application/probe/REFITProbeSystemServer.java

src/refit/application/rezk/REZKTestClientReadWrite.java

src/refit/application/rezk/REZKTestServer.java

src/refit/client/REFITBenchmark.java

src/refit/client/REFITClientLibrary.java

src/refit/client/REFITLibByz.java

src/refit/client/REFITLibSpider.java

src/refit/client/REFITLibSteward.java

src/refit/client/REFITReplyCertificate.java

src/refit/client/REFITStewardReplyCertificate.java

src/refit/client/policy/REFITProbeShiftPolicy.java

src/refit/communication/REFITConnection.java