(GH-1059) Deprecate old config elements

The top level config settings for chocolatey.config had a couple of
elements that were deprecated once configSettings section became
availalbe and settings could be set with the choco config command. Mark
those settings as deprecated and up for removal.

src/chocolatey/infrastructure.app/configuration/ConfigFileSettings.cs

@@ -26,12 +26,11 @@ namespace chocolatey.infrastructure.app.configuration
     [XmlRoot("chocolatey")]
     public class ConfigFileSettings
     {
+        [Obsolete("This will be removed in v1 of Chocolatey")]
         [XmlElement(ElementName = "cacheLocation")]
         public string CacheLocation { get; set; }
 
-        [XmlElement(ElementName = "containsLegacyPackageInstalls")]
-        public bool ContainsLegacyPackageInstalls { get; set; }
-
+        [Obsolete("This will be removed in v1 of Chocolatey")]
         [XmlElement(ElementName = "commandExecutionTimeoutSeconds")]
         public int CommandExecutionTimeoutSeconds { get; set; }