annotations: allows template variables to be used in tag filter

Add documentation for postgres query builder

Fix some megacheck issues

Team member labels

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

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

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

The "Decimals" value was incorrectly applied to the metric value used to calculate the gauge display in addition to the text value (so a "Decimals" value of "1" turns "45.1%" into "50%" in the gauge display even though the label still correctly says "45.1%").

Fix anonymous usage stats for authentication types

[metrics]enabled = false should disable the /metrics endpoint.

Just wanted to reduce the amount of files/folders in root

[skip ci]