Opt out from normal SSL X509 PKI usage

Allows to set custom trust anchors (CA, intermediate, server cert, or any
 other certificate in the trust chain is fine)
Added blob column to database holding the binary of the trusted certificate
Added dialog to display/delete certificate per account
Stubs/Ideas for UI enhancements:
	- Display fingerprint on initial trust question dialog
	- Pretty dialog of certificate contents
	- Radio buttons for selection dialog
	- Move UI stuff to XML
	- Make UI more fancy