* src/Makefile.am (Gnumeric-impl.o): This depends on Gnumeric.h,
Gnumeric-impl.c doesn't.

Reinstate Perl plugin.
* plugins/perl/Makefile.am: Clean up build.
* plugins/perl/ext/Gnumeric.xs (register_function):
Use FunctionCategory and `function_add_args' API instead of
`install_symbol'.
(marshal_func): Update to new callback prototype.
* plugins/perl/ext/Makefile.PL.in ('INC'): Use @top_srcdir@ rather
than @srcdir@/../../...

* doc/C/Makefile.am: Misc. srcdir != builddir fixes.
* configure.in (GNOME_PRINT_CFLAGS): Fix typo.