Update add panel flow

Clicking outside TimePicker (Angular & React versions) should close it

Changes default interpolation for Stackdriver filter to be regex. Fixes #15182

For the filter expression, a better default is to
interpolate multi variables as a regex rather than
the default globbing pattern.

Also, uses the real TemplateSrv class rather than
stubbing it in the tests.

Handle onPaste because of bug in this Slate version

docs: fixes #14940

Added custom scrollbar and remember scroll pos to jump back to same scroll pos when going back to dashboard from edit mode

Better stackdriver logo (bigger + svg)

* grafana/master: (54 commits)
  now /api/login/ping returns Response
  fix: Explore: Query wrapping on long queries #15222
  fix: Set ace editor min height to avoid problem with scrollbar overlapping ace content #15122
  fix: Data source picker in panel queries options should overlap content below, including ace scrollbar #15122
  fix util for splitting host and port
  changelog: add notes about closing #14231
  fixing logging action
  devenv: switching back using loki master plus various fixes
  Fix save provisioned dashboard modal
  Add AWS/Neptune to metricsMap and dimensionsMap
  did not add file, removing centerered
  Legend toggle should only trigger a re-render, not a refresh
  first stuff
  updated snapshot
  Adding pointer to colorpicker
  Minor post review changes
  More style tweaks to panel option group add button
  Made some style tweaks
  setting margin on label
  Make runQueries action independent from datasource loading
  ...

deletes auth token on signout

Adding ValueMappingsEditor to Storybook