Refactored checked_convert_to_int to use number_as_integer.
Made datum serialization format use datum_serialized_type_t instead of datum_t::type_t.
Merge branch 'sam_1427' into sam_1426
Made datum serialization use varint serialization for numeric datums that are integral.
Merge branch 'next' into sam_1426
Removed unused number_as_integer declaration in datum.hpp.
Made blocker_pool_t be a class, not a struct.
Made the blocker pool specify the stack size for blocker pool threads to be the same as COROUTINE_STACK_SIZE (which is 128 KB).
Made us actually pass the stack size attr to pthread_create in the blocker pool.
re-adds protobuf_implementation to JS driver
Add missing "err." in the js driver

Review 879 by @neumino
JavaScript driver version 1.9.0-1
Merge branch 'v1.9.x' into sam_1425
Merge branch 'sam_1425' into v1.9.x
Merge branch 'v1.9.x' into next
Manually implemented var_captures_t move operators.
Fix typo in reql docs

Review 916 by @neumino
Fix import statement in python driver

Closes #1438
Review over IRC by @neumino
Merge branch 'sam_1426' into next
Replaced decltype usage in validate.cc with auto usage.