Use ssl_mode for mysql and add docs
add docs for the new parameters in config

Tolerate ssl_mode without client authentication

Client cert is not necessary for a SSL connection. So we tolerate
failure if client cert is not provided.
Improve error message if missing server_cert_name and mode is not
skip-verify.

Zoom out on double click in graphs

Fix empty username in http log for /render calls

Displaying Last UpdatedBy as Metadata

fixes #3555, path of table panel option error

Add memcache as session provider

Removed export/view permission from a dashboard viewer

cleared in these call. Not just get username before the call is
executed. see #3405 for more info.

tech(systemjs): finally starting to get systemjs and typescript and runtime loading to work together in a manner that I want it to.. took forever