glcd driver updates:

1. Remove connection type header files and put prototypes locally and in
   glcd-drivers.h. Don't fall into the pitfall of too many header files again.
2. Create a separate frame buffer structure (this allows easier re-use of
   the frame buffer functions).
3. Add a function to retrieve pixel values from framebuffer.
4. Add the 'serdisplib' connection type.
5. Support display width that are not a multiple of 8 (e.g. 122x32).

acinclude.m4

@@ -173,6 +173,16 @@ dnl			else
 			if test "$enable_libpng" = yes ; then
 				GLCD_DRIVERS="$GLCD_DRIVERS glcd-glcd-png.o"
 			fi
+			AC_CHECK_HEADERS([serdisplib/serdisp.h],[
+				AC_CHECK_LIB(serdisp, serdisp_nextdisplaydescription,[
+					AC_DEFINE(HAVE_SERDISPLIB,[1],[Define to 1 if you have working serdisplib])
+					LIBSERDISP="-lserdisp"
+					GLCD_DRIVERS="$GLCD_DRIVERS glcd-glcd-serdisp.o"
+				],[
+					AC_MSG_WARN([serdisp library not working])
+				])
+			])
+			AC_SUBST(LIBSERDISP)
 			DRIVERS="$DRIVERS glcd${SO}"
 			actdrivers=["$actdrivers glcd"]
 			;;