Partials not working in Mustache template

[zdeseb]

There is feature in Mustache templates called Partials which allows to include one template into another.

This could be very useful feature (especially while constructing more complex queries) but it doesn't work correctly in ES pre-registered templates

Steps to reproduce:

1. create file child.mustache file in config/scripts folder with content
   "match_all": {}
2. wait until ES compiles this file what is indicated by following text in log
   compiling script file [...\config\scripts\child.mustache]
3. create file parent.mustache file in config/scripts folder with content

{
  "query": {
    {{>child}}
  }
}

1. When ES tries to compile parent template, following error occurs

failed to load/compile script [parent]
org.elasticsearch.common.mustache.MustacheException: Template 'child' not found

It looks like ES understands partial syntax but is unable to find existing template.

I'm facing this problem in ES 1.4.4 but the same problem was in 1.2.2 too

[clintongormley]

Related to #10047

[clintongormley]

No plans to implement partials, given then outcome of #10047