pkg/tsdb: fix ineffassign isues

fix CircleCI gometalinter test

graphite: use a query when testing data source

postgres: adjust timeFilter, timeFrom and timeTo macro examples

Merge branch 'annotations-created' of https://github.com/ryantxu/grafana into ryantxu-annotations-created

removed padding and moved carrot

for some reason the linter lints files in /vendor
which it should not. So we have to remove it until
it works as expected

ref #10381

this makes it possible for the plugin repo
to provide the correct package if arch and os matters

influxdb: Check before assuming first column to be 'time'

Add gometalinter to CircleCI

remove unused variables detected by varcheck

[skip ci]

add tabs and search filter to new panel control

External auth refactor

Fix performance issue with running bra run for go run build.go build

Specify expected encoding for access/secret key

* master:
  changelog: adds note about closing #11613 and #11602
  fix: sign in link should have target self to trigger full page reload, fixes #11626
  codespell: exclude by words instead of files
  Use sort.Strings() (gosimple)
  Remove unused return value assignment (gosimple)
  Remove unnecessary fmt.Sprintf() calls (gosimple)
  Merge variable declaration with assignment (gosimple)
  Use fmt.Errorf() (gosimple)
  Simplify make() (gosimple)
  Use raw strings to avoid double escapes (gosimple)
  Simplify if expression (gosimple)
  Simplify comparison to bool constant (gosimple)
  Simplify error returns (gosimple)
  Remove redundant break statements (gosimple)