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()

cache.h

@@ -1698,5 +1698,6 @@ int stat_validity_check(struct stat_validity *sv, const char *path);
 void stat_validity_update(struct stat_validity *sv, int fd);
 
 int versioncmp(const char *s1, const char *s2);
+void sleep_millisec(int millisec);
 
 #endif /* CACHE_H */