Move instance urls to be last in the pattern list.

Prevents shadowing of short url patterns like '^admin/$'
Create a list of reserved instance url names, Fixes #561
Fix regression introduced by bb8a9a9, always serialize unchecked boxes
Merge pull request #618 from maurizi/master

Fix regression introduced by bb8a9a9, always serialize unchecked boxes
Merge pull request #609 from maurizi/topic/561/reservedInstanceUrls

Reserved instance urls