yardopts: look for more Markdown files.

But exclude vendored stuff.
qt: update 4.8.6 bottle.
yaz 5.4.3

Version bump. Please don’t merge before #33288. It’s an optional
dependency, but makes life a little less risky.
yaz: update 5.4.3 bottle.

Closes #33294.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
cairo: update 1.12.16_1 bottle.
ffmpeg: update 2.4.2 bottle.
fontconfig: update 2.11.1 bottle.
gcc: update 4.9.1 bottle.
gd: update 2.1.0_2 bottle.
gobject-introspection: update 1.42.0 bottle.
libgcrypt: update 1.6.2 bottle.
libidn: update 1.29 bottle.
libsndfile: update 1.0.25 bottle.
libusb: update 1.0.19 bottle.
libusb-compat: update 0.1.5 bottle.
lua: add 5.2.3_1 bottle.
mad: update 0.15.1b bottle.
objective-caml: update 4.01.0_1 bottle.
pango: update 1.36.8 bottle.
popt: update 1.16 bottle.