Fix all functions vs 'all' function. Fixes #758

Author: commonsensesoftware

src/Common.OData.ApiExplorer/AspNet.OData/Builder/DefaultODataQueryOptionDescriptionProvider.cs

@@ -242,7 +242,7 @@ static void AppendAllowedOptions( StringBuilder description, ODataQueryOptionDes
             }
 
             if ( context.AllowedFunctions != AllowedFunctions.None &&
-                 context.AllowedFunctions != AllowedFunctions.All )
+                 context.AllowedFunctions != AllowedFunctions.AllFunctions )
             {
 #pragma warning disable CA1308 // Normalize strings to uppercase
                 var functions = context.AllowedFunctions.ToString().ToLowerInvariant();

test/Microsoft.AspNet.OData.Versioning.ApiExplorer.Tests/AspNet.OData/Builder/DefaultODataQueryOptionDescriptionProviderTest.cs

@@ -245,7 +245,7 @@ public static IEnumerable<object[]> FilterDescriptionData
                     new []{ "category", "price", "quantity" },
                     AllowedLogicalOperators.All,
                     AllowedArithmeticOperators.All,
-                    AllowedFunctions.All,
+                    AllFunctions,
                     "Restricts the set of items returned. The allowed properties are: category, price, quantity.",
                 };
             }