commands.debugrevspec: add an option to print the optimized expression tree This will be used in an upcoming patch to test that the optimizer works.

tests: killdaemons.py for windows distinguishes access violation and terminated To distinguish between access violaition (process belonging to another user) and a terminated process, PROCESS_QUERY_INFORMATION must be enabled. But TerminateProcess still raises error 5 in both cases. Therefore check before if the process has already terminated.

tests: killdaemons.py for checks reason when getting no process handle