Properly escape the per-node STONITH parameters

https://bugzilla.novell.com/show_bug.cgi?id=888637
URIencoding doesn't seem to be the right thing to do in this case. This will result in values like: ```param%3D%22value%22```. AFAICT we need to translate ```"``` to ```&quot``` and probably ```<``` and ```>``` the their proper HTML entities here.