Simplify IndexCrudAction pagination configuration merging

We now more or less disregard any changes to controller::paginate since it's deprecated, please modify paginator::settings directly
remove unused subject assingment
only copy controller paginate settings if they are set
[Crud Index Action] Rename _computePaginationConfig to paginationConfig and make it public

Also move the triggering of beforePaginate into _handle
[Crud Index Action] Move paginationConfig up below viewVar method since its now public, and they should be first in the method ordering of the class
Merge pull request #35 from jippi/feature/refactor-index-action-pagination

Simplify IndexCrudAction pagination configuration merging