Add missing files to Makefile.am
diff --git a/Makefile.am b/Makefile.am
index 8054f98..3c5ce07 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -68,9 +68,12 @@
   csharp/protos/map_unittest_proto3.proto                                    \
   csharp/protos/unittest_custom_options_proto3.proto                         \
   csharp/protos/unittest_import_public_proto3.proto                          \
+  csharp/protos/unittest_import_public.proto                                 \
   csharp/protos/unittest_import_proto3.proto                                 \
+  csharp/protos/unittest_import.proto                                        \
   csharp/protos/unittest_issues.proto                                        \
   csharp/protos/unittest_proto3.proto                                        \
+  csharp/protos/unittest.proto                                               \
   csharp/src/AddressBook/AddPerson.cs                                        \
   csharp/src/AddressBook/Addressbook.cs                                      \
   csharp/src/AddressBook/AddressBook.csproj                                  \
@@ -100,6 +103,7 @@
   csharp/src/Google.Protobuf.Test/Compatibility/TypeExtensionsTest.cs        \
   csharp/src/Google.Protobuf.Test/DeprecatedMemberTest.cs                    \
   csharp/src/Google.Protobuf.Test/EqualityTester.cs                          \
+  csharp/src/Google.Protobuf.Test/ExtensionSetTest.cs                        \
   csharp/src/Google.Protobuf.Test/FieldCodecTest.cs                          \
   csharp/src/Google.Protobuf.Test/FieldMaskTreeTest.cs                       \
   csharp/src/Google.Protobuf.Test/GeneratedMessageTest.cs                    \
@@ -119,13 +123,17 @@
   csharp/src/Google.Protobuf.Test/TestCornerCases.cs                         \
   csharp/src/Google.Protobuf.Test/TestProtos/ForeignMessagePartial.cs        \
   csharp/src/Google.Protobuf.Test/TestProtos/MapUnittestProto3.cs            \
+  csharp/src/Google.Protobuf.Test/TestProtos/TestMessagesProto2.cs           \
   csharp/src/Google.Protobuf.Test/TestProtos/TestMessagesProto3.cs           \
   csharp/src/Google.Protobuf.Test/TestProtos/UnittestCustomOptionsProto3.cs  \
   csharp/src/Google.Protobuf.Test/TestProtos/UnittestImportProto3.cs         \
   csharp/src/Google.Protobuf.Test/TestProtos/UnittestImportPublicProto3.cs   \
+  csharp/src/Google.Protobuf.Test/TestProtos/UnittestImportPublic.cs         \
+  csharp/src/Google.Protobuf.Test/TestProtos/UnittestImport.cs               \
   csharp/src/Google.Protobuf.Test/TestProtos/UnittestIssues.cs               \
   csharp/src/Google.Protobuf.Test/TestProtos/UnittestProto3.cs               \
   csharp/src/Google.Protobuf.Test/TestProtos/UnittestWellKnownTypes.cs       \
+  csharp/src/Google.Protobuf.Test/TestProtos/Unittest.cs                     \
   csharp/src/Google.Protobuf.Test/WellKnownTypes/AnyTest.cs                  \
   csharp/src/Google.Protobuf.Test/WellKnownTypes/DurationTest.cs             \
   csharp/src/Google.Protobuf.Test/WellKnownTypes/FieldMaskTest.cs            \