Initial commit of a more flexible mailtransport, including support for Akonadi resource-based transports.

Changes include:
* separate config widgets for each transport type (smtp, sendmail, akonadi)
* a nice KAssistantDialog for adding transports
* support for renaming transports in the management widget

A lot is still TODO, and this will eventually need an API review.


svn path=/branches/kdepim/soc/kdepimlibs/; revision=977460