Merge pull request #13 from VDVsx/master

Add isAccountValid and isMessageValid invokables.
[nemo-qml-plugin-email] Add some folder id APIs.
Merge pull request #15 from kananoja/master

[nemo-qml-plugin-email] Add some folder id APIs.
Merge pull request #14 from VDVsx/master

Extend emailmessage object to support loading messages.
[nemo-qml-plugin-email] Detect drafts folders properly.

Export drafts to remove server when remote folder is detected.