(mysql driver) add logging, implement emailsBelongToSameAccount, addKeyToEmailRecord, checkAuth, and pubkeysForEmail

(mysql driver) when unit_test is specified at open time, we use a database with a random name, and clean it up upon cdb connection lose.

rework deployment configuration (using less of the express mechanism) so that configuration options are available at all levels

rework deployment configuration (using less of the express mechanism) so that configuration options are available at all levels

add an explicit db.open() call which will provide the hook for passing configuration information into the db layer

basic testing of all db.js apis complete, also completed implementation of identitysync to check installed pubkeys.

consolidate db.checkAuth and db.checkAuthHash - move all bcrypt knowledge out of the persistence layer

tests of db.isStaged, db.stageEmail, db.gotVerificationSecret, and db.emailKnown.  also add some documentation in db.js for various apis

initial stubbing of db.js tests, also generalize db.js so that the path where the database resides may be configured

added CSRF protection and started moving actions that need it to POST, which automatically inherits CSRF protection. Not complete yet