WIP on tim_server_status
Implements rethinkdb.server_status pseudo-table.
Add a test for rethinkdb.server_status. It mostly passes.
Made rethinkdb.server_status correctly report ports even if they were chosen by the OS instead of being specified directly.
Merge branch 'reql_admin' into tim_server_status
Many minor style and bug fixes:
- Remove spurious backslash in serve.cc
- Use uint16_t for ports instead of int
- Remove spurious include in datum_adapter.hpp
- Remove anonymous namespace in server_status.cc
- Remove incorrect comment in server_common.cc
- Be rigorous about home threads in pseudo-table backends
Use microtime_t instead of time_t.
Actually use uint16_t for ports instead of int. (My previous commit forgot to change the one place that actually mattered.)
Merge branch 'reql_admin' into tim_server_status

Conflicts:
	test/full_test/interface.test