Support regex or array template pattern match

[PhaedrusTheGreek]

I would like to be able to define multiple match patterns on the same index template, to avoid situations where many identical templates must be maintained separately.

PUT /_template/template_1
{
  "template": ["my_logs-*","your_logs-*"],
  "settings": {
    "number_of_shards": 1
  },
  "mappings": {
  ...
  }
}