Used signbit instead of std::signbit function.
Used the "using namespace std" trick to get signbit working on multiple systems.
Plagiarized @atnnn's fix for sorted_datum_stream_t to get GCC 4.4.3 working.
Merge branch 'sam_1444' of github.com:rethinkdb/rethinkdb into sam_1444
Added threadnum_t and used it everywhere you would want it used.
Removed some RSI comments that are basically off-topic.
fixing broken admin cli 'help' command
fixing broken admin cli 'help' command
Added pb_print back to utils.hpp.
Merge branch 'next' into sam_1445
Merge branch 'v1.9.x' into next
Merge branch 'sam_1445' into next
Add support for marking tests as flaky

Review 926 by @tryneus
Closes #736
Merge branch 'next' into sam_1444
Merge branch 'sam_1444' into next
Merge branch 'next' into sam_1429_datum_serialization_tests