Take down condition subsystem at shutdown/reboot

Leave the system as it was when we found it.  Also, we'll build things
on top of cond_is_available() to handle pre bootstrap and pre shutdown
tasks.

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

src/cond.h

@@ -46,7 +46,10 @@ int  cond_clear_noupdate(const char *name);
 void cond_reassert    (const char *pat);
 void cond_deassert    (const char *pat);
 
+int  cond_is_available(void);
+
 void cond_init        (void);
+void cond_exit        (void);
 
 #endif	/* FINIT_COND_H_ */