Renaming Main.WebHome page breaks the search

Apparently users rename the Home page. This happens for a lot of reasons, some include not knowing how to change the title, wanting a different URL, etc.

After the rename, the Search stops working.

A. One solution would be to move technical pages from Main space, like Search, Tags, Activity Stream, etc. and make this space a 'content' only space that the users can alter.

B. Another solution would be to uncheck by default the "preserve children" checkbox.

C. Another solution would be to display what applications would be affected by the rename, just like we do for 'Delete' action.

Issue reported by lucaa