Explore: Add multiline syntax highlighting to query field

* brian2222-patch-1:
  removes testdata from getting started
  Update getting_started.md

ref #11433

Internal metrics: starts counters at zero

annotations: allows template variables to be used in tag filter

Add documentation for postgres query builder

Fix some megacheck issues

Team member labels

list of datasources updated in section: dashboards, panels, the buildingblocks of grafana...

See,
$ gometalinter --vendor --disable-all --enable=megacheck --disable=gotype --deadline 6m ./... | grep ID
alert.go:193:15:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
alert.go:252:18:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
annotation.go:113:12:warning: sess.Table("annotation").Id is deprecated: use ID instead  (SA1019) (megacheck)
org.go:136:24:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
org.go:169:16:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
org_users.go:24:21:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
org_users.go:88:12:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
org_users.go:141:21:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
plugin_setting.go:103:12:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
preferences.go:97:12:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
quota.go:119:17:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
quota.go:221:17:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
team.go:77:24:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
user.go:243:16:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
user.go:267:13:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
user.go:282:13:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
user.go:313:12:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
user.go:475:3:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
user.go:479:13:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)
user.go:493:13:warning: sess.Id is deprecated: use ID instead  (SA1019) (megacheck)

See,
$ gometalinter --vendor --disable-all --enable=megacheck --disable=gotype --deadline 6m ./... | grep SQL
alert.go:43:9:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
alert_notification.go:122:12:warning: sess.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
annotation.go:226:12:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
dashboard.go:228:9:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
dashboard.go:302:10:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
dashboard.go:416:9:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
dashboard.go:635:12:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
migrations/user_mig.go:137:9:warning: sess.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
plugin_setting.go:29:10:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
quota.go:41:12:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
quota.go:84:13:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
quota.go:143:12:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
quota.go:186:13:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
quota.go:234:12:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
team.go:172:12:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
team.go:199:17:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
team.go:223:9:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
temp_user.go:99:10:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
temp_user.go:124:10:warning: x.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
user.go:375:3:warning: sess.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
user.go:377:3:warning: sess.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)
user.go:379:3:warning: sess.Sql is deprecated: use SQL instead.  (SA1019) (megacheck)

Permissions to redux

fix hipchat color code used for "no data" notifications

docs: include active directory ldap example and restructure

- the non-nested query field schema did not allow for multi-line
  highlighting
- added explicit code schema and a `makeValue` function that enforces
  the nested structure
- replaced vendored prism-slate adapter with official slate-prism
  package
- renamed language to syntax

Since #13212 adhoc filters are being gathered, in Explore the template
  service has no variables set and then throws when iterating over them.

without starting the counter as zero Grafana will not send any metrics
to graphite using the bridge.

Fix gauge display accuracy for "percent (0.0-1.0)"

Added underline to links in table

use pluginName consistently when upgrading plugins

fix: use datasource cache for backend datasources