LCD core move buf ptr and address look up function viewport struct

I'm currently running up against the limitations of the lcd_draw functions
I want these functions to be able to be used on any size buffer not
just buffers with a stride matching the underlying device

[DONE] allow the framebuffer to be decoupled from the device framebuffer
[DONE need examples] allow for some simple blit like transformations
[DONE] remove the device framebuffer from the plugin api
[DONE}ditto remote framebuffer
[DONE] remove _viewport_get_framebuffer you can call struct *vp = lcd_set_viewport(NULL) and vp->buffer->fb_ptr

while remote lcds may compile (and work in the sim) its not been tested on targets

[FIXED] backdrops need work to be screen agnostic

[FIXED] screen statusbar is not being combined into the main viewport correctly yet

[FIXED] screen elements are displayed incorrectly  after switch to void*

[FIXED] core didn't restore proper viewport on splash etc.

[NEEDS TESTING] remote lcd garbled data

[FIXED] osd lib garbled screen on bmp_part

[FIXED] grey_set_vp needs to return old viewport like lcd_set_viewport

[FIXED] Viewport update now handles viewports with differing buffers/strides by copying to the main buffer

[FIXED] splash on top of WPS leaves old framebuffer data (doesn't redraw)
[UPDATE] refined this a bit more to have clear_viewport set the clean bit and have skin_render do its own screen clear
scrolling viewports no longer trigger wps refresh
also fixed a bug where guisyncyesno was displaying and then disappearing

[ADDED!] New LCD macros that allow you to create properly size frame buffers in you desired size without wasting bytes
(LCD_ and LCD_REMOTE_)
LCD_STRIDE(w, h) same as STRIDE_MAIN
LCD_FBSTRIDE(w, h) returns target specific stride for a buffer W x H
LCD_NBELEMS(w, h) returns the number of fb_data sized elemenst needed for a buffer W x H
LCD_NATIVE_STRIDE(s) conversion between rockbox native vertical and lcd native stride (2bitH)
test_viewports.c has an example of usage

[FIXED!!] 2bit targets don't respect non-native strides
[FIXED] Few define snags

Change-Id: I0d04c3834e464eca84a5a715743a297a0cefd0af

apps/plugins/fire.c

@@ -30,6 +30,7 @@
 #ifndef HAVE_LCD_COLOR
 #include "lib/grey.h"
 #endif
+static fb_data *lcd_fb = NULL;
 
 #if (LCD_WIDTH == 112) && (LCD_HEIGHT == 64)
 /* Archos has not enough plugin RAM for full-width fire :( */
@@ -251,7 +252,7 @@ static inline void fire_draw(struct fire* fire)
 #ifndef HAVE_LCD_COLOR
         dest = draw_buffer;
 #else
-        dest = *rb->lcd_framebuffer + LCD_WIDTH * y + FIRE_XPOS;
+        dest = lcd_fb + LCD_WIDTH * y + FIRE_XPOS;
 #endif
         end = dest + FIRE_WIDTH;
 
@@ -379,6 +380,8 @@ enum plugin_status plugin_start(const void* parameter)
     rb->lcd_set_mode(LCD_MODE_PAL256);
 #endif
 
+    struct viewport *vp_main = rb->lcd_set_viewport(NULL);
+    lcd_fb = vp_main->buffer->fb_ptr;
     ret = main();
 
 #if defined(HAVE_LCD_MODES) && (HAVE_LCD_MODES & LCD_MODE_PAL256)