Nuked migrations
Various enhancements:
- Only allow RSA keys (as other types don't work)
- Added a few relevant fields to certificates
- User proper tempfile for CSR's (as opposed to hardcoded one, that could lead to problems with multiple users)
- Show sensible data in certificate list
Minor ui changes:

- better placement of github logo
- lose the unnecessary h1's on lists
Add serials to CA:s, mark CSR:s as signed when signing. Add sensible string presentation for certificates.