initialized sem_gcfin in vm_startup().

fixed a new problem in error message output bound for stderr.
fixed  wrong timeout value calculatin in exec.c

moo/kernel/System.moo

@@ -98,6 +98,7 @@ class System(Apex)
 
 	method(#class,#primitive) _popCollectable.
 	method(#class,#primitive) collectGarbage.
+	method(#class,#primitive) gc.
 	method(#class,#primitive) return: object to: context.
 
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