Update mStartPage to make language selection work on other pages

We should offer language selection on any start page such as
decrypt or system read only. However, if the mStartPage variable
was not being updated properly so selecting a different language
was dumping the user back on either the decrypt prompt or the
system read only page. This patch set fixes the problem and places
the user back on the proper page when they choose a new language.

Change-Id: I5153d3b9525d8c93d3863f4b17ecf55b5209e3c7

gui/gui.cpp

@@ -613,8 +613,10 @@ static int runPages(const char *page_name, const int stop_on_page_done)
 	DataManager::SetValue("tw_page_done", 0);
 	DataManager::SetValue("tw_gui_done", 0);
 
-	if (page_name)
+	if (page_name) {
+		PageManager::SetStartPage(page_name);
 		gui_changePage(page_name);
+	}
 
 	// Raise the curtain
 	if (gCurtain != NULL)
@@ -945,7 +947,7 @@ error:
 
 extern "C" int gui_start(void)
 {
-	return gui_startPage(NULL, 1, 0);
+	return gui_startPage("main", 1, 0);
 }
 
 extern "C" int gui_startPage(const char *page_name, const int allow_commands, int stop_on_page_done)

gui/pages.cpp

@@ -1565,6 +1565,10 @@ void PageManager::RequestReload() {
 	mReloadTheme = true;
 }
 
+void PageManager::SetStartPage(const std::string& page_name) {
+	mStartPage = page_name;
+}
+
 int PageManager::ChangePage(std::string name)
 {
 	DataManager::SetValue("tw_operation_state", 0);

gui/pages.hpp

@@ -140,6 +140,7 @@ public:
 	static void ReleasePackage(std::string name);
 	static int RunReload();
 	static void RequestReload();
+	static void SetStartPage(const std::string& page_name);
 
 	// Used for actions and pages
 	static int ChangePage(std::string name);