rust-chg: depend on log and tokio_timer
I'll start porting the daemon management functions from chg of C, which
will be difficult to debug without some logging facility. AFAIK, the log
crate is easy-to-use and widely used.
tokio_timer provides sleep() helper to be used while spawning a server
process.
#require docutils gettext
$ $TESTDIR/check-gendoc fr
checking for parse errors