(loadgen) tons of fixes to handle request failures without mucking up the local user database - issue #838, issue #785, issue #787, issue #784

when loadgen emits errors, indicate what activity was being performed when the error was encountered.

implement a 'maximum request time' for bcrypt work.  server now fails more gracefully under backbreaking load, returning 503s to clients of the authenticate_user api.  update loadgen to be less dramatic about, but still display, 503 errors.  first part of issue #787 - a partial fix for #785 in dere too

implement graceful shutdown of bcrypt compute processes.  fix bcrypt.get_rounds (was throwing an exception)

fix regression in keysigner - ensure non-default VAR_PATH is relayed to compute processes - issue #213

remove the deep __heartbeat__ checks performed from browserid (the webhead), while dbwriter should ping the database to ensure health - closes #566

(loadgen) fix console output at startup - properly message # of pre-created users or users to be created via API

(loadgen) add '-l' option to list activites, and '-a' option to specify a list of activites to run (ignoring others).  simplify '-o' so all this stuff uses the same mechanism

more issue #598 - add test and fix for other places where exceptions leak out of JWCrypto and cause 500 errors rather than 200 failure responses.

the verifier is more helpful if you leave off content-type headers, also did you know we support application/json?  closes #643

(loadgen) add -u option that allows one to specify a numeric range which will make load testing with a large database possible - issue #504

(loadgen) implement assertion generation in loadgen client, hook up signup and signin flows - issue #504

(loadgen) now starts up, generates 30 keypairs, adds 30 users - simulated signup mostly updated to new apis - issue #504

repairing load_gen - issue #504 - update pathing, alter fake_verification WSAPI to query the database rather than to use email interception (which no longer works)

initial implementation of request forwarding, cookies set from dbwriter are still not being properly passed through - issue #460