Idea for using decoders' special features

[Corona688]

Some of these decoders, MikMOD in particular, have extra features that
are pretty difficult to take advantage of unless we want to make
function calls with 3 dozen variables or huge weird structures that
contain everything imaginable.  Just the same, it'd be a shame if we
couldn't use them.

What I'd like to be able to do, is assign the responsibility for
interpreting these special features up to the decoders, while still
having the ability to set them explicitly if we want to.  Could we add a
const char * parameter to Sound_NewSampleFromFile() etc. and pass it
commandline-like strings?  Like:

sample = Sound_NewSampleFromFile("someawful.mod", NULL, 4096 *
4,"-e:7");

if we wanted to set MikMOD's echo level to seven.  And if we just want
the default, we can give it NULL.  Thoughts?