cmd_server update
fix rounding error in timeout that was causing epoll_wait spin
more aggressive rounding up for timeout
add double-conversion lib from v8 for jsonstream
make build work
update application to use new api and use signalfd for SIGINT.
qutex and rendez house cleaning
introduce method name matching into HTTP server routing
add hs::app_json hs::app_json_utf8
uri: use std::forward where appropriate
introduce metrics::intervals, sliding time aggregate statistics
use nostacksize_t to evolve deprecated APIs
omit needless namespace refs; use nullopt
test metrics::intervals