remove pixelflinger from recovery

Recovery now draws directly to the framebuffer by rolling its own
graphics code, rather than depending on libpixelflinger.

The recovery UI is modified slightly to eliminate operations that are
slow with the software implementation: when the text display / menu is
turned on, it now appears on a black background instead of a dimmed
version of the recovery icon.

There's probably substantial room for optimization of the graphics
operations.

Bug: 12131110
Change-Id: Iab6520e0a7aaec39e2ce39377c10aef82ae0c595
diff --git a/screen_ui.cpp b/screen_ui.cpp
index a72da58..c87c00c 100644
--- a/screen_ui.cpp
+++ b/screen_ui.cpp
@@ -87,7 +87,7 @@
 {
     pagesIdentical = false;
     gr_color(0, 0, 0, 255);
-    gr_fill(0, 0, gr_fb_width(), gr_fb_height());
+    gr_clear();
 
     if (icon) {
         gr_surface surface = backgroundIcon[icon];
@@ -203,12 +203,12 @@
 // Should only be called with updateMutex locked.
 void ScreenRecoveryUI::draw_screen_locked()
 {
-    draw_background_locked(currentIcon);
-    draw_progress_locked();
-
-    if (show_text) {
-        SetColor(TEXT_FILL);
-        gr_fill(0, 0, gr_fb_width(), gr_fb_height());
+    if (!show_text) {
+        draw_background_locked(currentIcon);
+        draw_progress_locked();
+    } else {
+        gr_color(0, 0, 0, 255);
+        gr_clear();
 
         int y = 0;
         int i = 0;