vf_select: Drop a debug av_log with an unchecked double to enum conversion

CC: libav-stable@libav.org
configure: Globally add ZLIB_CONST to CPPFLAGS if zlib is enabled
pgssubdec: Check RLE size before copying

Make sure the buffer size does not exceed the expected
RLE size.

Prevent an out of array bound write.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Bug-Id: CVE-2013-0852

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>