Support for CER/DER formatted client certificates

Also only files with PEM file extension are treated as PEM files. Unsupported formats will cause an error log message and not be imported.

@@ -8,7 +8,7 @@
     </Request>
   </Items>
   <ContextParameters>
-    <ContextParameter Name="Valid-PEM-Path" Value="U:\projekt\MjukaCertifikat\Interna_Certifikat_Okt_2016\8946019907112000070.pem" />
+    <ContextParameter Name="PEM" Value="U:\projekt\MjukaCertifikat\Interna_Certifikat_Okt_2016\8946019907112000070.pem" />
   </ContextParameters>
   <ValidationRules>
     <ValidationRule Classname="Microsoft.VisualStudio.TestTools.WebTesting.Rules.ValidateResponseUrl, Microsoft.VisualStudio.QualityTools.WebTestFramework, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" DisplayName="Response URL" Description="Validates that the response URL after redirects are followed is the same as the recorded response URL.  QueryString parameters are ignored." Level="Low" ExectuionOrder="BeforeDependents" />
@@ -33,7 +33,7 @@
     <WebTestPlugin Classname="LIL_VSTT_Plugins.ClientCertificatePlugin, LIL_VSTT_Plugins, Version=1.3.0.0, Culture=neutral, PublicKeyToken=null" DisplayName="Client Certificate" Description="(C) Copyright 2016 LIGHTS IN LINE AB&#xD;&#xA;Sätter webtestet att använda ett specifikt client cert för SSL. Certifikatet behöver inte installeras i certstore först.">
       <RuleParameters>
         <RuleParameter Name="pCertificatePath" Value="" />
-        <RuleParameter Name="pCertificatePathParameter" Value="Valid-PEM-Path" />
+        <RuleParameter Name="pCertificatePathParameter" Value="PEM" />
         <RuleParameter Name="pCertificatePassword" Value="" />
         <RuleParameter Name="pCertificatePasswordParameter" Value="" />
         <RuleParameter Name="pDebug" Value="True" />