cgroup: refactor, use a unified hierarchy for finit

As of now, the default finit cgroup behavior is to use a unified
hierarchy of controllers under /sys/fs/cgroup/finit.

We mount cpu,cpuacct,cpuset,memory (if available) and gain the
ability to control our three major groups: init, system, user.

The default CPU share setup is ~10% for init and user, and 90% for
system.  These are guaranteed CPU shares to ensure we do not starve
PID 1 or user processes.  Support for configuring these limits will
be added in a later commit.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/cgroup.h

@@ -26,7 +26,7 @@
 
 void cgroup_init   (void);
 
-int cgroup_user    (char *name);
-int cgroup_service (char *cmd, char *id, int pid);
+int cgroup_user    (char *name, int pid);
+int cgroup_service (char *name, int pid);
 
 #endif /* FINIT_CGROUP_H_ */