gui: use XML-based page for splash screen instead of a static jpg

For devices with an unusual aspect ratio, stretching a bitmap to
the screen resolution is sub-optimal. So let's reuse our XML engine
that allows assembling the splash screen from individual parts.

The splash page is loaded from a separate XML file for quick loading.

Change-Id: I2d3dad26e42fcefaf563dacdf0ffa61f209dada1
diff --git a/gui/pages.cpp b/gui/pages.cpp
index def2629..c455662 100644
--- a/gui/pages.cpp
+++ b/gui/pages.cpp
@@ -64,7 +64,6 @@
 
 std::map<std::string, PageSet*> PageManager::mPageSets;
 PageSet* PageManager::mCurrentSet;
-PageSet* PageManager::mBaseSet = NULL;
 MouseCursor *PageManager::mMouseCursor = NULL;
 HardwareKeyboard *PageManager::mHardwareKeyboard = NULL;
 bool PageManager::mReloadTheme = false;
@@ -1421,10 +1420,6 @@
 			LOGERR("Package %s failed to load.\n", name.c_str());
 	}
 
-	// The first successful package we loaded is the base
-	if (mBaseSet == NULL)
-		mBaseSet = mCurrentSet;
-
 	mCurrentSet = pageSet;
 
 	if (pZip) {
@@ -1500,8 +1495,6 @@
 	}
 	if (mCurrentSet == set)
 		SelectPackage(name);
-	if (mBaseSet == set)
-		mBaseSet = mCurrentSet;
 	delete set;
 	GUIConsole::Translate_Now();
 	return 0;
@@ -1518,6 +1511,8 @@
 	PageSet* set = (*iter).second;
 	mPageSets.erase(iter);
 	delete set;
+	if (set == mCurrentSet)
+		mCurrentSet = NULL;
 	return;
 }