Cosmetics: Use the GCD function when possible and rename it to use English.
PPagePlayback: Disable auto zoom factor control when it is not used.
gccbuild.bat: remove unneeded quotes
reindent checkyear.sh and add bat files in the files to check
Revert "actually disable C4995 and C4996 for udf.cpp"

This reverts commit 03ca3eff5fccbfe6bfc1583789d4fe91af8b1900.
build.bat, mpc-hc_setup.iss : add ICL13 support
update ffmpeg (n0.8-18359-ge4e36a4)