Wiki mirroring implementation (#3233)

* Implement wiki mirroring, add Update mirrors operation to admin dashboard

* bindata.go update after merge

* Implement checking Git repo endpoint existence, support for BB included

* Remove admin dashboard operation
Fix bindata.go

* Apply gofmt to repo model file

* Try to remove bindata from PR

* Revert accepted wiki names change in favor of better system

* Remove unused imports

templates/repo/wiki/view.tmpl

@@ -46,7 +46,7 @@
 		</div>
 		<div class="ui dividing header">
 			{{.title}}
-			{{if .IsRepositoryWriter}}
+			{{if and .IsRepositoryWriter (not .IsRepositoryMirror)}}
 				<div class="ui right">
 					<a class="ui small button" href="{{.RepoLink}}/wiki/{{.PageURL}}/_edit">{{.i18n.Tr "repo.wiki.edit_page_button"}}</a>
 					<a class="ui green small button" href="{{.RepoLink}}/wiki/_new">{{.i18n.Tr "repo.wiki.new_page_button"}}</a>