Change type of provisioningProfile property to path.

Change-Id: I92540f7250c0b3425d6b5aaec498198e3c6a3463
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Introduce xcodeSdkName and xcodeSdkVersion properties.

Change-Id: I6572b085c24cf8ba6d1a41dab267182cabe6aab8
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>