reduced the size of shard tracker actors by removing unnecessary state variable. Because we have a large number of these actors these extra state variables add up to a lot of memory
* Detail names now all start with an uppercase character and contain no underscores. Ideally these should be head-first camel case, though that was harder to check.
* Type names have the same rules, except they allow one underscore (to support a usage pattern Context_Type). The first character after the underscore is also uppercase.
* Use seconds instead of milliseconds in details.
Added a check when events are logged in simulation that logs a message to stderr if the first two rules above aren't followed.
This probably doesn't address every instance of the above problems, but all of the events I was able to hit in simulation pass the check.
fix: the master did not monitor for the failure of remote logs
stop merge attempts when a data center is failed
fixed a variety of other problems with data distribution when a data center is failed
Evan Tschannen