Fix crash issue due to the bad fix of touchscreen hanging issue

This crash issue is a regression due to
6f4140a281 which was intended to fix a
touchscreen hanging bug.
The crash issue is fixed in this commit, as well the touchscreen hanging
issue thanks to the answer from StackOverflow:

http://stackoverflow.com/questions/34816597/messagebox-not-responsing-in-wm-activateapp-on-touchscreen/34825851#34825851

PowerEditor/src/Notepad_plus.h

@@ -383,16 +383,7 @@ private:
 	//For Dynamic selection highlight
 	CharacterRange _prevSelectedRange;
 
-	struct ActivateAppInfo final
-	{
-		bool _isActivated = false;
-		int _x = 0;
-		int _y = 0;
-	}
-	_activeAppInf;
-
 	//Synchronized Scolling
-
 	struct SyncInfo final
 	{
 		int _line = 0;

PowerEditor/src/NppBigSwitch.cpp

@@ -1347,24 +1347,24 @@ LRESULT Notepad_plus::process(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lPa
 			return notify(notification);
 		}
 
-		case NPPM_INTERNAL_CHECKDOCSTATUS:
 		case WM_ACTIVATEAPP:
 		{
 			if (wParam == TRUE) // if npp is about to be activated
 			{
-				const NppGUI & nppgui = pNppParam->getNppGUI();
-				if (LOWORD(wParam) && (nppgui._fileAutoDetection != cdDisabled))
-				{
-					_activeAppInf._isActivated = true;
-					
-					//checkModifiedDocument();
-					// Make checkModifiedDocument as thread to avoid Notepad++ hanging while user uses touch screen to activate Notepad++ windows
-					HANDLE hThread = CreateThread(NULL, 0, &CheckModifiedDocumentThread, NULL, 0, NULL);
-					::CloseHandle(hThread);
-					return FALSE;
-				}
+				::PostMessage(hwnd, NPPM_INTERNAL_CHECKDOCSTATUS, 0, 0);
 			}
-			break;
+			return FALSE;
+		}
+
+		case NPPM_INTERNAL_CHECKDOCSTATUS:
+		{
+			const NppGUI & nppgui = pNppParam->getNppGUI();
+			if (nppgui._fileAutoDetection != cdDisabled)
+			{
+				checkModifiedDocument();
+				return TRUE;
+			}
+			return FALSE;
 		}
 
 		case NPPM_INTERNAL_GETCHECKDOCOPT:

PowerEditor/src/resource.h

@@ -407,7 +407,7 @@
     // Used by Doc Monitor plugin
     //
 	#define NPPM_INTERNAL_CHECKDOCSTATUS (NPPMSG + 53)
-    // VOID NPPM_CHECKDOCSTATUS(BOOL, 0)
+    // VOID NPPM_CHECKDOCSTATUS(0, 0)
     // check all opened documents status.
     // If files are modified, then reloaod (with or without prompt, it depends on settings).
     // if files are deleted, then prompt user to close the documents