[vorbis-dev] Bug fix, win32 stuff

[Jonathan Blow]

There was a bug in the new ov_open_callbacks where it would
not zero out some member variables of the file info struct,
and if a file was not successfully opened this would cause
a crash at destruct time.  Fixed.

I've also made some changes so that vorbis will compile
cleanly under win32 without one having to muck around with it.

I have added a "vorbis_vc6" directory which contains project
and workspace files for Visual C++ 6.  os.h, lpc.c and
codec.h were changed in minor ways.  I am doing a lot of
development under win32 so I will be maintaining this.

In order to get everything compiling cleanly across both win32
and linux, I had to add a new file "os_types.h" into the public
include directory.  This contains the defintions of types such
as int64_t.  It was necessary to put that there because
some of the other public include files use these types.

I could have moved os.h into the public include directory but
it seemed that os.h includes some things that the user really
does not need to see, and this will only become more so over
time.  So I made the choice of splitting it into 2 files.
I am of course open to suggestions if anybody has a better
solution.

Also in vorbisfile.c, I added that optimization I was 
discussing where a faster sample-conversion loop is used if
an endian-switch is not needed.

    -Jonathan.

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/