(chocolatey#62) Add new config value DefaultPushSource

This config value will be used to set the default source used for
choco push. The default value will be overridden if the user specifies
--source. The value goes into config.PushCommand.DefaultSource

src/chocolatey/infrastructure.app/ApplicationParameters.cs

@@ -194,6 +194,7 @@ public static class ConfigSettings
             public static readonly string WebRequestTimeoutSeconds = "webRequestTimeoutSeconds";
             public static readonly string UpgradeAllExceptions = "upgradeAllExceptions";
             public static readonly string DefaultTemplateName = "defaultTemplateName";
+            public static readonly string DefaultPushSource = "defaultPushSource";
         }
 
         public static class Features

src/chocolatey/infrastructure.app/builders/ConfigurationBuilder.cs

@@ -267,6 +267,7 @@ private static void set_config_items(ChocolateyConfiguration config, ConfigFileS
             config.Proxy.BypassOnLocal = set_config_item(ApplicationParameters.ConfigSettings.ProxyBypassOnLocal, configFileSettings, "true", "Bypass proxy for local connections. Available in 0.10.4+.").is_equal_to(bool.TrueString);
             config.UpgradeCommand.PackageNamesToSkip = set_config_item(ApplicationParameters.ConfigSettings.UpgradeAllExceptions, configFileSettings, string.Empty, "A comma-separated list of package names that should not be upgraded when running `choco upgrade all'. Defaults to empty. Available in 0.10.14+.");
             config.DefaultTemplateName = set_config_item(ApplicationParameters.ConfigSettings.DefaultTemplateName, configFileSettings, string.Empty, "Default template name used when running 'choco new' command. Available in 0.12.0+.");
+            config.PushCommand.DefaultSource = set_config_item(ApplicationParameters.ConfigSettings.DefaultPushSource, configFileSettings, string.Empty, "Default source to push packages to when running 'choco push' command. Available in 0.12.0 +.");
         }
 
         private static string set_config_item(string configName, ConfigFileSettings configFileSettings, string defaultValue, string description, bool forceSettingValue = false)

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

@@ -665,6 +665,7 @@ public PackCommandConfiguration()
     public sealed class PushCommandConfiguration
     {
         public string Key { get; set; }
+        public string DefaultSource { get; set; }
         //DisableBuffering?
     }