Make test suite runnable for ES 1.4

This PR runs all the riot tests without causing cancellations. Please note that a number of tests fail but the test suite itself at least runs through. All changes were made against the latest official Elasticsearch version 1.4.

* fixes a couple of URLs for HTTP requests
* renames index names to no use underscore as prefix
* adjusts `match_all` queries
* adjusts logic of some of the API functions, e.g. aliases with filter
* snapshot functionality has changed too much, test does not apply anymore in this way