Description of problem:

agent.c is doing a fetch of all parameters for a given device name in a fence
level for a specific node.  So, what was happening is that the following would
happen for say, off, off, on, on for the same APC device "foo":

option=off
port=8
switch=0
option=off
port=7
switch=0
option=on
port=8
switch=0
option=on
port=7
switch=0
agent=fence_apc
ipaddr=foo
login=apc
passwd=apc

The net result of running this operation is that only "port 7, on" actually
happens.  Thus, fencing succeeds even though nothing has occurred to actually
fence the node, even though the configuration is correct.

The patch here fixes fenced and fence_node to call (in this case) fence_apc 4
times by using the index instead of the device name to determine parameters:

option=off
port=8
switch=0
agent=fence_apc
ipaddr=foo
login=apc
passwd=apc
<done>

option=off
port=7
switch=0
agent=fence_apc
ipaddr=foo
login=apc
passwd=apc
<done>

option=on
port=8
switch=0
agent=fence_apc
ipaddr=foo
login=apc
passwd=apc
<done>

option=on
port=7
switch=0
agent=fence_apc
ipaddr=foo
login=apc
passwd=apc
<done>

This affects every configuration where off/on pairs are used.  As I said, I
don't think *any* of our agents do the "multi-operation" bit, and it would be
significantly more work to make them work this way than it is to just use this
patch ;)

Version-Release number of selected component (if applicable): 1.32.1-1,
CVS/STABLE, CVS/HEAD, CVS/RHEL4, CVS/RHEL4U2

How reproducible: 100%

Steps to Reproduce: See above
  
Actual results: One operation performed (in the above case, "port 7 on")

Expected results: Four operations performed (port 8 off, port 7 off, port 8 on,
port 7 on).