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).

server/drivers/glcd-drivers.h

@@ -1,7 +1,7 @@
 /** \file server/drivers/glcd-drivers.h
  * Connection type registry for glcd driver.
  *
- * File file contains includes and pointers to the connection type's init()
+ * File file contains prototypes and pointers to the connection type's init()
  * function.
  */
 
@@ -12,18 +12,22 @@
 # include "config.h"
 #endif
 
-/* Include connection type header below */
+/* Include prototypes for initialization functions below */
 #ifdef HAVE_PCSTYLE_LPT_CONTROL
-# include "glcd-t6963.h"
+int glcd_t6963_init(Driver *drvthis);
 #endif
 #ifdef HAVE_LIBPNG
-# include "glcd-png.h"
+int glcd_png_init(Driver *drvthis);
+#endif
+#ifdef HAVE_SERDISPLIB
+int glcd_serdisp_init(Driver *drvthis);
 #endif
 
 /* symbolic names for connection types */
 #define GLCD_CT_UNKNOWN		0
 #define GLCD_CT_T6963		1
 #define GLCD_CT_PNG		2
+#define GLCD_CT_SERDISP		3
 
 /** Structure linking symbolic names to initialization routines */
 typedef struct ConnectionMapping {
@@ -44,6 +48,9 @@ static const ConnectionMapping connectionMapping[] = {
 #endif
 #ifdef HAVE_LIBPNG
 	{"png", GLCD_CT_PNG, glcd_png_init},
+#endif
+#ifdef HAVE_SERDISPLIB
+	{"serdisplib", GLCD_CT_SERDISP, glcd_serdisp_init},
 #endif
 	/* default, end of structure element (do not delete) */
 	{NULL, GLCD_CT_UNKNOWN, NULL}