Write to logInfo.txt only after identities.txt have been correctly updated

[xiaokangwang]

Currently, when running verifier on a local system, it will resume from the point recorded in logInfo.txt. However, it overrides logInfo.txt with the most recent data point before entries between Previous Size and Current Size is scanned for monitored-values. By shutting down the monitor while it is running, the identities.txt could have missing entries that could potentially break the monitoring process.

[haydentherapper]

This sounds good to me.

Overall this needs to be reworked and each of these should be able to fail independent of one another without causing the verifier to stop.