akonadi:

• add CollectionColorAttribute - used to store and sync the calendar color, currently colors are stored in a config file with akonadi id <-> color. So we have already only the single connection over the akonadi id, so we can store the color directly in akonadi and can sync them by backend. Currently we only made kolab resource make use of that but other backendens can implement that too (f. ex. owncloud ).

EntityDisplayAttribute has also a color setting, but it is background color and this one is already used by the ETM to change the background color. And EntityDisplayAttribute is never synced to the server, s owe would need to hack around, that only the color property is synced and all other are keeped local.

akonadi-calendar:

• add multi calendar support (see T1102 and D587)
• strip out use of schedulingID
• fixing exception and sceduling
• add support to act with multiple identities (to be able to act as delegator of someone else)