Removed references of Virtual Wiki from the User guide and acceptance tests.
Remove virtual wiki code from (save-) properties responder
Remove virtual page dependency from FitNesseUtil.
Removed VirtualEnabledPageCrawler.
Removed VirtualCouplingExtension and VirtualCouplingPage.
removed Extension et al
only keep PageCrawler.setDeadEndStrategy where needed.
Cleaned up WikiPage. Removed unused methods.
Merge branch 'drop-virtual-wiki'