when alsapid is preloaded libasound is not loaded yet
for some unknown reason, late call to dlvsym() fails as well,
at least for mididings (python loads _mididings.so that
implicitly loads libasound.so)
this changeset implements the late symbol lookup,
because it makes the code smaller
the actual fix is to LD_PRELOAD libasound.so as well
hexter.so has an init function with same name as the one in alsapid.so
so the hexter one was not being called and the descriptor pointer
that is returned was NULL
Nedko Arnaudov