Obsolete API using throwOnUnexpectedArg

[natemcmaster]

In 2.6, API using "ThrowOnUnexpectedArg" has been made obsolete in favor of the enum UnrecognizedArgumentHandling. This API will be removed in 3.0.
Here is how the old behavior maps to the new API.

ThrowOnUnexpectedArg	UnrecognizedArgumentHandling
true	Throw
false	StopParsingAndCollect

Here are some examples of obsolete code and the recommended replacement.

Obsolete constructors

var app = new CommandLineApplication(throwOnUnexpectedArg: false);

Recommended replacement

var app = new CommandLineApplication
{
    UnrecognizedArgumentHandling = UnrecognizedArgumentHandling.StopParsingAndCollect
};

Obsolete properties

CommandLineApplication app;
app.ThrowOnUnexpectedArg = true;
app.ThrowOnUnexpectedArg = false;

[Command(ThrowOnUnexpectedArgument = false)]
private class MySubcommand
{}

Recommended replacement

CommandLineApplication app;
app.UnrecognizedArgumentHandling = UnrecognizedArgumentHandling.Throw;
app.UnrecognizedArgumentHandling = UnrecognizedArgumentHandling.StopParsingAndCollect;

[Command(UnrecognizedArgumentHandling = UnrecognizedArgumentHandling.StopParsingAndCollect)]
private class MySubcommand
{}

Obsolete methods

app.Command("subcommand", subcmd =>
{
    subcmd.Description = "My subcommand";
},
throwOnUnexpectedArg: false);

Recommended replacement

app.Command("subcommand", subcmd =>
{
    subcmd.Description = "My subcommand";
    subcmd.UnrecognizedArgumentHandling = UnrecognizedArgumentHandling.StopParsingAndCollect;
});