Title change should create new slug (and redirect the old slug)

[dentarg]

Example page: https://wiki.starkast.net/star_wars:_rogue_one_-_2017-12-28

In the old version of wikimum, we had page alias support. Maybe that could be use to solve title changes.

[dentarg]

In the old version of wikimum, we had page alias support

wikimum/app/models/page.rb

Lines 22 to 37 in be64b4e

	def self.find_by_title(title = nil, user = nil)
	return false if title.nil?
	shorthand = title.to_shorthand
	page = Page.find(:first,
	:conditions => [ "shorthand_title = ? AND #{read_conditions_for(user)}", shorthand ],
	:include => [ :permissions, :updater ])
	unless page
	page_alias = Alias.find(:first, :conditions => [ "alias = ?", shorthand ], :include => :page)
	page = page_alias.page if page_alias
	end
	page
	end