- refactored elasticsearch AR to make type and index available in
  instantiate(), issue #1313

fixes #2281

Improved `QueryBuilder::buildLimit()` to support big numbers

Change <code>array_reduce</code> with anonimous function variant to easy string collection from pieces of unions.

Using short array syntax.

Change buildUnion method to be ready to accept parameters in <code>['all' => $all, 'query' => $query]</code> format for division to "UNION" and "UNION ALL" constructions.

Change passing parameters to array with two elements – 'all' which means if we use UNION or UNION ALL construction and 'query' which is our sql query that will be at right of construction.

Forget one ";" :D

Delete some spaces from result string.

Change union method to accept also <code>$all</code> variable. TRUE means that we must results <code>UNION ALL</code> construction, FALSE – that <code>UNION</code>.

Fixed some errors – syntax with ";" after closure function and also moved building of unions queries into this function.

Change using of implode to convert array of queries to union to array_reduce. Result of this changing is that code feel difference between two selects that connects with UNION and two selects that connects with UNION ALL.

add ability to use an array in multi columns parameters

Fixes #2016: removed ability to declare scopes in ActiveRecord leaving it to ActiveQuery. Changed documentation accordingly.