check: add libavcodec/vda_internal.h to SKIPHEADERS-$(CONFIG_VDA)
build: export library dependencies in ${name}_FFLIBS

Removes an ugly $(if) to avoid conflicts with $(FFLIBS-) in the
top-level MAkefile.
lavf: add av_stream_get_side_data
disable -rpath-link on Solaris

The Solaris -rpath linker option parser is greedy.
build: add Solaris symbol versioning

The Solaris linker does not support globs in linker scripts for
symbol versioning (this is a GNU extension). Let's instead borrow
make_sunver.pl from GCC to make a description file that works
with the Solaris linker.