Ability to update any preference field

[GoogleCodeExporter]

Currently there no option to alter existing preference's properties outside 
from the value.

The way of patching a existing preference is limited to removing and creating 
it again, or alternatively bypassing the API and using directly talking with 
the database.

Quick to-do:

- Introduce update_pref() function
- This function can update any property of a preference string (potentially 
excluding user_name and name).
- Uses name and user_name for selecting

If user_name and name are excluded for usability/readability purposes, 
introduce two shorthand functions too, e.g:

- rename_pref()
- change_pref_owner()

Original issue reported on code.google.com by jukka.m.svahn on 12 Nov 2012 at 4:46

[GoogleCodeExporter]

Original comment by jukka.m.svahn on 12 Nov 2012 at 4:47

• Changed state: Assigned

[GoogleCodeExporter]

This issue was closed by revision r4693.

Original comment by jukka.m.svahn on 12 Nov 2012 at 8:51

• Changed state: Fixed