libtool has matured a lot since the last time i looked at it (years ago)

libtool has matured a lot since the last time i looked at it (years ago)
so we now use it to handle the details of building shared libraries and
the linker flags for the main executable.

in theory this should bring a lot more portability to the dynloader
subsystem and enable us to do things like transparently detect GNU vs Sun
linkers on solaris, for example