Add support for writing to stdout

[kohlrabi]

This pull request contains the code which will allow to write to stdout instead of a file, by giving the option --stdout. With that it is possible to pipe the output of ww2ogg to another program for further processing, for example by revorb.

[hcs64]

This is cool, thanks. Does it really work with revorb?

A few suggested improvements:

• There's a number of commented out cout lines, I'd prefer these to be made cerr as well
• I like to check with isatty() before writing to stdout to avoid spewing binary onto the console

Also I'd prefer if you split out the compiler change into a separate pull request, some of my systems still have the i586-mingw32msvc compiler.

[kohlrabi]

Thanks for the comments, I will split up both changes so that you can pull the stdout patch separately. I have recently tested with revorb (actually, that was the reson for the patch), which supports taking data from stdin by specifying "-" as input file.

[qlyoung]

@kohlrabi think you could finish up this PR? would be awesome to have it :)

[Mgamerz]

+1, would appreciate this. I will manually implement this to prevent having to do a bunch of disk I/O in my project, but it would be nice to have it official.

[Mgamerz]

The one thing about this I have noted is that the receiving program must manually modify the length of the file it receives - the piece of data after RIFF as it is not known at the start time it seems.

[hcs64]

Cool, thanks! I'll take a look over this soon.

Edit: Oops, that was meant for #23. I'm sorry to have left thing hanging for 4+ years, still not sure what's the best way to approach this. I'll try to get this paged back in and make a decision this weekend.