Some libvisual-plugins fixes

[David Leverton]

Hi,

I found a few bugs in libvisual-plugins, patches attached.

First is pretty trivial: the lv_analyzer plugin doesn't get build due to a
small error in configure.ac.

Second is to fix library linking: the Makefile.ams use the LIBS variable
to specify the libraries to be linked in, but LIBADD should be used
instead.  In cases where LIBS is set globally it works anyway (AIUI this
variable is supposed to be set by configure, so does get used), but
automake doesn't recognise it in the form actor_foo_la_LIBS.  The result
is that the OpenGL plugins don't actually get linked against libGL.

Third is an 64-bit fix for JESS.

Fourth is a partial 64-bit fix for G-Force - it's enough to make the
plugin to run without crashing, but I couldn't get it to work properly.
I'm sending it anyway so that if someone else wants to fix it (I might try
again myself some time, but no promises...) they don't have to start from
scratch.  Note that I'm not sure if all the changes are needed - to be
honest, I just got sick of messing with it, and just saved what I already
had - but I'm pretty sure they won't break it on platforms where it
already works.