Khard

- New option "show_uids" in config file to disable uid column in contact table

- Sort contact table by first or last name (take note of changed behaviour of "sort" option)
- New option -g, --group-by-addressbook to group contact table by address book
- Changes in config file:
- New group: contact table
- new option: sort to sort contact table by first or last name
- New option: group_by_addressbook to group contact table by address book
- Moved show_nicknames option from group "general" to group "contact table"

- Fixed uid dictionary creation

- Cancel without further actions if the opened contacts editor is closed without saving (determined
by modification date of template file)

- Use of module atomicwrites to securely write vCards to disk

- Added support for multiple instances of one vCard attribute