Support more iso date formats in vCard revision strings

This fixes https://github.com/skarra/ASynK/issues/48

OwnCloud uses a different format string for revision strings
than what we have seen with other CardDAV servers. To their
credit the format is a iso8601 parseable string. Let's just
parse them
Workaroud a OwnCloud 7 "bug" where phone type is not mentioned

Fixes https://github.com/skarra/ASynK/issues/48
Make state.get_latest_config_filename a static method

This is to make it easier to use that method from other sources
Add a test suite for parsing .vcf files in our code

- Add a few sample vcf files for testing purposes
- Some changes to the CDContact class to ensure it can be
  instantiated standalone - without a folder or db instance
  tied to it.
Fix minor error in the bbdb test when cmd line argument is passed
Additional debug logs while logging into a CD server
add another auth file (for having passwords) to .gitignore