Fixed the following issues:

Issue #1321: New-AzureQuickVM: WinRMCertificate option should check for an exportable private key in x509object
Issue #1322: New-AzureQuickVM: Uploaded WinRMCertificate/X509Certificates should have the password set correctly
Fixed the following issue:
#1319: Export-AzureVM : System.Security.Cryptography.KeySizes cannot be serialized because it does not have a