Application should have "forced" command, rather than "default"

[g105b]

The setDefaultCommand function is used to allow calling a command that's registered on the Application without calling the command, which is useful for applications that only have one command.

However, the function was designed with one particular use-case in mind: a command that takes only Parameters and not NamedParameters. With NamedParameters, this functionality is impossible to use.

If the setDefaultCommand function was renamed to forceCommand, this would tell the Application that the provided command should always be run.

Would be extra useful to have #15 implemented for this too.