Improve Page Rename

[redimp]

As discussed in #210, renaming a page could make use of some features:

• a) the links to attachments on the page itself (and other pages, using the same attachments)
• b) the links to the page form other pages
• c) corner case: When renaming attachments, the links shoudl be updated, see https://github.com/redimp/otterwiki/issues/65

These should be optional when renaming pages, so that you have to check a box, when you want links to be auto updated. There are cases, where users rename pages on a regular basis and don't want the links to be updated.