Modify clang-format according to #207 (see comment)

.clang-format

@@ -16,7 +16,7 @@ AllowShortCaseLabelsOnASingleLine: false
 AllowShortFunctionsOnASingleLine: None
 AllowShortIfStatementsOnASingleLine: false
 AllowShortLoopsOnASingleLine: false
-AlwaysBreakAfterDefinitionReturnType: TopLevel
+AlwaysBreakAfterDefinitionReturnType: true
 BinPackArguments: false
 BinPackParameters: false
 BreakBeforeBinaryOperators: NonAssignment