-dlopen library change does not cause main program relink

[Kevin P. Fleming]

Here's a hard one to fix:

My program has about 30 plugin modules. The Makefile.am provides 
-dlopen <modulepath> for each one, so that if the user chooses to 
disable shared libraries, the plugins will be preloaded into the 
(static) program binary. This works fine.

However, the generated Makefile does not have a dependency on 
src/handlers/unpack.la for src/nALFS, so if a make is done, then the 
src/handlers/unpack.c file is modified, a subsequent make causes 
src/handlers/unpack.la to be rebuilt but src/nALFS _is not relinked_. 
Relinking would not be necessary if the plugin module was being built 
as a shared library, but when it's not, relinking the binary(ies) 
using it is mandatory.

Granted, this only affects developers and not really end users all 
that much, and a "make clean" also takes care of it. It'd be nice if 
this link dependency could be translated into the Makefile in some way.