[rtmpdump] Build a shared library for librtmp

[Howard Chu]

Arne Morten Kvarving wrote:
> hi,
>
> i'm currently working on integrating librtmp into xbmc
> (http://www.xbmc.org) based on the patches from highlandsun.
>
> since we're somewhat a high profile target, and want to cover our
> arses, i'm writing it using a dlopen() approach to allow for drop-in
> support. this means i need a shared library built, currently your
> build system only builds a static one. from the looks of it the
> easiest spot to add this is in the rtmpdump/ directory, since we
> already have the defines for the lib deps etc. however, it feels kinda
> bad. how should i proceed? i have a simple patch to do it in the
> rtmpdump dir, but feels wrong..

A patch was submitted to build as a shared library, but the library needs a 
few other small changes before I consider it safe.