libtool and Mingw DLLs - bindir/libdir solution - requesting comments

[Max Bowsher]

I've thought of a way to reliably get bindir from a Makefile.
In libtool.m4, the command line to invoke libtool is defined - we can
add --bindir="$(bindir)" to it, so that libtool knows explictly what the
bindir is, even when overridden at 'make install' time.

Any comments welcome,

Max.


The background on why this is necessary:

Windows shared libraries are in 2 parts, the DLL (which should go in bindir)
and the import library (which should go in libdir). Without the above
workaround, libtool has no way of knowing where bindir is whilst installing
a shared library.