(GH-8) Refine Posh Prompting

Both the caption and the message should be displayed to users during
PowerShell prompting. The choices menu should look more similar to how
it would originally look in PowerShell.

src/chocolatey/infrastructure/powershell/PoshHostUserInterface.cs

@@ -198,7 +198,8 @@ private static string[] get_hotkey_and_label(string input)
 
         public override int PromptForChoice(string caption, string message, Collection<ChoiceDescription> choices, int defaultChoice)
         {
-            this.Log().Warn(caption.escape_curly_braces());
+            if (!string.IsNullOrWhiteSpace(caption)) this.Log().Warn(caption.escape_curly_braces());
+            if (!string.IsNullOrWhiteSpace(message)) this.Log().Warn(ChocolateyLoggers.Important, message.escape_curly_braces());
 
             string[,] promptData = build_hotkeys_and_plain_labels(choices);
 
@@ -208,14 +209,14 @@ public override int PromptForChoice(string caption, string message, Collection<C
             {
                 choicePrompt.Append(String.Format(
                     CultureInfo.CurrentCulture,
-                    "|{0}> {1} ",
+                    "[{0}] {1} ",
                     promptData[0, element],
                     promptData[1, element]));
             }
 
             choicePrompt.Append(String.Format(
                 CultureInfo.CurrentCulture,
-                "[Default is ({0}]",
+                "(default is \"{0}\")",
                 promptData[0, defaultChoice]));
 
             while (true)
@@ -255,7 +256,9 @@ public override PSCredential PromptForCredential(string caption, string message,
 
         public override PSCredential PromptForCredential(string caption, string message, string userName, string targetName, PSCredentialTypes allowedCredentialTypes, PSCredentialUIOptions options)
         {
-            this.Log().Warn(caption.escape_curly_braces());
+            if (!string.IsNullOrWhiteSpace(caption)) this.Log().Warn(caption.escape_curly_braces());
+            if (!string.IsNullOrWhiteSpace(message)) this.Log().Warn(ChocolateyLoggers.Important, message.escape_curly_braces());
+
             if (string.IsNullOrWhiteSpace(userName))
             {
                 this.Log().Warn("Please provide username:");