3400: ArvadosResourceList returns all items (paging as necessary) unless limit() is specified.
* ArvadosResourceList#each returns results incrementally.  ArvadosResourceList#all (or ArvadosResourceList#results) prefetches the entire list.
* Added tests.  Fixed tests.
* Removed hardcoded limit() in cases where it was apparent that it was being used as a workaround for the paging problem.
* Removed obsolete name_link code (including CollectionsController#choose override) that was causing tests to fail.
3400: Too much code that assumes it can call .first over and over without
incurring an API call each time (silly).
3400: Remove ArvadosResourceList#all
3400: ArvadosResourceList retains api token that is active when it is created.
Tweaked fetch-multiple-pages loop.  Made #each_page protected.  _paging sets
fetch_multiple_pages(false).
3400: Stub out obsolete #links_for and remove result_links and related test.
Set @result_limit and @result_offset to nil unless @fetch_multiple_pages ==
false.  Add test for limit > default page size.
3400: test limit between server maxpagesize and 2x server maxpagesize.

Conflicts:
	apps/workbench/test/unit/arvados_resource_list_test.rb
Merge branch 'master' into 3400-workbench-all-items
Merge branch '3400-workbench-all-items' closes #3400