Merge branch 'js/sleep-without-select'

Portability fix.

* js/sleep-without-select:
lockfile: wait using sleep_millisec() instead of select()
lockfile: convert retry timeout computations to millisecond
help.c: wrap wait-only poll() invocation in sleep_millisec()
lockfile: replace random() by rand()

diff --cc cache.h
Simple merge

diff --cc help.c
Simple merge

diff --cc lockfile.c
Simple merge