gui: simplify blanktimer

- get rid of separate thread, check timer in rendering thread instead
- use an enum for the blanking state instead of magic integers
- move #ifdefs for TW_NO_SCREEN_TIMEOUT inside blanktimer class
- move some #includes and enum TOUCH_STATE to pages.hpp

Change-Id: Id4b104e3680dc5db41d8ba85e32d722cf4086299
diff --git a/gui/pages.cpp b/gui/pages.cpp
index a1a6346..aae85ae 100644
--- a/gui/pages.cpp
+++ b/gui/pages.cpp
@@ -45,14 +45,9 @@
 
 #include "rapidxml.hpp"
 #include "objects.hpp"
-#ifndef TW_NO_SCREEN_TIMEOUT
 #include "blanktimer.hpp"
-#endif
 
 extern int gGuiRunning;
-#ifndef TW_NO_SCREEN_TIMEOUT
-extern blanktimer blankTimer;
-#endif
 
 std::map<std::string, PageSet*> PageManager::mPageSets;
 PageSet* PageManager::mCurrentSet;
@@ -1197,10 +1192,8 @@
 
 int PageManager::Update(void)
 {
-#ifndef TW_NO_SCREEN_TIMEOUT
-	if(blankTimer.IsScreenOff())
+	if(blankTimer.isScreenOff())
 		return 0;
-#endif
 
 	int res = (mCurrentSet ? mCurrentSet->Update() : -1);