[API] [1.0] Updated the "Get Index Alias" APIs to the 1.0 changes

See: http://www.elasticsearch.org/guide/en/elasticsearch/reference/master/_indices_apis.html#_indices_apis

Related:

* elasticsearch/elasticsearch@411739fe3b5b2410fa9594edf27087718162225f
* elasticsearch/elasticsearch#4743
[API] [1.0] Updated the "Alias Exists" APIs to the 1.0 changes

See: http://www.elasticsearch.org/guide/en/elasticsearch/reference/master/_indices_apis.html#_indices_apis

Related:

* elasticsearch/elasticsearch@411739fe3b5b2410fa9594edf27087718162225f
* elasticsearch/elasticsearch#4743