Made throttled_pmap not use co_semaphore_t.
Made throttled_pmap_runner_t be separate from pmap_runner_one_arg_t.
Made coro_t::spawn... functions use rvalue references and std::forward.
Made throttled_pmap use new_semaphore_t.
Made throttled_pmap actually wait for acquisition...
Added <utility> to callable_action.hpp.
Merge branch 'sam_spawn_move' into next
bump Python driver to 1.13.0-3
release notes for 1.13.4

Closes #2918
fixing continuation of sindex postconstruction after restart
adding test for continuation of sindex post-construction after server restart
Per #2930 use better error message

Conflicts:

	src/rdb_protocol/shards.cc
Distinguish grouped & non grouped cases in errmsg

Conflicts:

	src/rdb_protocol/shards.cc
Handle case of grouped data with only one group
Add edge detection cases for bizarre size limits
Disallow bizarre size limits
adding r.binary support to the server
adding support for r.binary with nested terms to the drivers
adding tests for r.binary with nested terms
Fix stupid compilation error