Add support for inlining arguments, possibly from a file

[xenomachina]

It would be nice to be able to be able to enable the processing of arguments from files. For example/ something like:

myProgram --foo -@bar --quux

might read arguments from the file bar, so that if bar contained:

--hello world
--so-long "thanks for all the fish"

this would behave as if the arguments were:

myProgram --foo --hello world --so-long "thanks for all the fish" --quux

(with the exception that an option or positional argument list cannot be partly in the file and partly outside of it)