Define macros in examples/unicode.h to use Unicode argv
on Windows. Keep char everywhere on Unix since it handles
UTF-8 without any change.
Impact:
- All fopen () and SHCreateStreamOnFile(),
- All fprintf() printing file paths,
- All strcmp() used with "-",
- File path parsing,
- Gif reading.
Concerned executables from examples/ and extras/:
anim_diff, anim_dump, vwebp, vwebp_sdl,
cwebp, dwebp, gif2webp, img2webp,
webpmux, webpinfo, webp_quality, get_disto
When compiled on Windows with Unicode enabled, webpmux and
img2webp will not work when used with an argument file and
will print "Reading arguments from a file is a feature
unavailable with Unicode binaries."
BUG=webp:398
Change-Id: Ic55d222a3ce1a715f9c4cce57ecbe2705d5ce317
