[Gnash-dev] Configure doesn't friendly-warn for missing libspeexdsp headers

[TJ]

Building in a clean chroot environment (on Ubuntu) I found that
configure doesn't friendly-warn about the missing header file

speex/speex_resampler.h

which is in the "libspeexdsp-dev" package on Debian/Ubuntu.

The configure script does detect the header file isn't in place but
doesn't appear to make it obvious it is required:

checking for speex_resampler.h header using pkg-config... not found
checking for speexdsp-config... no
checking speex_resampler.h usability... no
checking speex_resampler.h presence... no
checking for speex_resampler.h... no
checking speexdsp/speex_resampler.h usability... no
checking speexdsp/speex_resampler.h presence... no
checking for speexdsp/speex_resampler.h... no
checking for speexdsp/speex_resampler.h... (cached) no
checking for speex_resampler.h... (cached) no
checking for speex_resampler.h header... not found
checking for libspeexdsp library using pkg-config... not found
...
        Speex flags are:  
        Speex libs are: -lspeex  

On Ubuntu I solved it with:

sudo apt-get install libspeexdsp-dev