webos-carddav-sync: Initial commit

Skeleton is copied from the WebOS synergy connector example at
https://developer.palm.com/content/api/dev-guide/synergy/creating-synergy-contacts-package.html

Parts of the Plaxo specific bits have been removed. Others have only been
commented out so far.
service: Add small and handy debug function.

Also start to use it in checkCredentialsAssistant
Service and ID rename.

It seems webos is not happy with dashes in service names. Remove
them and straight out some service names while doing so.
accounts/app: Change icon to WebOS ports logo for now.
service: Split the username input field into username and URL.

The default synergy connector validator has only two fields: username and
password. Given that CardDAV is not a central service with know infrastructure
we also need to specify an URL.

As a fast solution we are using the username input field for username as well as
URL. Combined are both with an @ sign. This commit splits this correctly and
fills in the internals for it.

Long term we want to use a custom validator for this. The docs do not really
describe them so some more investigation is needed before we have this.
service: Document some kown problems.

Add FIXMES for problem with account getting created even when returning false
and that we are missing to put the URL into the config store.
Rename the whole project to its, hopefully, final name: org.webosports.service.contacts.carddav
service: Account creation fails with wrong password.

This FIXME is now longer needed. Creation fails with wrong password.
README: Update to reflect the current status.