Share Kibana dashboards

[monicasarbu]

The purpose is to offer a way to make it easier for the users to share their own Kibana dashboards.

The following tasks need to be done:

• re-write import_dashboards in Golang, instead of having two versions, one in bash and one in powershell (done in Rewrite import_dashboards.sh script in go #2155)
• create an archive with all the Beats dashboards Create a beats-dashboards package #2298
• compile the import_dashboards script on different OS, and include it in the Beat package Package the import_dashboards go program #2303
• make it possible for community beats to package their dashboards. Per beat package dashboard target #2304
• update import_dashboards script to download & import the Elastic Beats dashboards of the same version without the need to pass the full url. Set the default URL in the import_dashboards program #2305
• update docs Update docs for managing Kibana dashboards #2324