* acconfig.h
* config.h.in
* configure.in: added --with-threads (taken from gtk+ configure.in)

* libgimp/Makefile.am: ugly hack to force libgimpi.a to get rebuilt since
libgimp.la compilations screws up the deps. Fixes relinking on make install.

* configure.in
* plug-ins/Makefile.am: other cleanups

* libgimp/gimp.c
* app/plug_in.c: pass INT32 instead of INT8 for gdisp_id since that's the
correct type

* app/preferences_dialog.c
* plug-ins/script-fu/script-fu-server.c
* plug-ins/tileit/tileit.c: warning fixups