Upgrade golang to 1.10

Documentation fix: "~/go" to "$GOPATH"

alerting: fixes validation error when saving alerts in dash

only use jwt token if it contains an email address

add comma templating format

If a panelId in the dashboard json is set to zero then the validation
silently fails. Instead of returning an error, it just ignores alerts and
saves the dashboard.

Add metrics that triggered alert to description in OpsGenie.

Pausing/un alerts now updates new_state_date

hide row actions for viewers

In "Install from source" section supposed that Grafana`s sources installed to `~/go` , but it is not always true. 
In other hand, `go get ..` command would install project to `$GOPATH`

https://golang.org/cmd/go/#hdr-Download_and_install_packages_and_dependencies

changed background for mobile menu background on light theme,

made drop-menu into link

ref #11053

closes #11126

Thresholds for Right Y axis

alerting: Limits telegram captions to 200 chars.

changed background for mobile menu background on light theme, increased font size in and added border-right in menu

The caption for inline images in Telegram is
limited to 200 characters.

Fixes #10975

fixes invalid link to profile pic when gravatar is disabled

closes #11112

closes #11097