fix some typos to silence the spellchecker CI

src/Base/StackWalker.cpp

@@ -305,7 +305,7 @@ public:
       if (GetFileAttributes(szTemp) == INVALID_FILE_ATTRIBUTES)
       {
         // ".local" file does not exist, so we can try to load the dbghelp.dll from the "Debugging Tools for Windows"
-        // Ok, first try the new path according to the archtitecture:
+        // Ok, first try the new path according to the architecture:
 #ifdef _M_IX86
         if ( (m_hDbhHelp == NULL) && (GetEnvironmentVariable(_T("ProgramFiles"), szTemp, 4096) > 0) )
         {

src/Doc/Document.mm

@@ -34,7 +34,7 @@
 <font BOLD="true" NAME="SansSerif" SIZE="12"/>
 <node CREATED="1193392755557" ID="Freemind_Link_1428395748" MODIFIED="1193392767045" TEXT="XML Model"/>
 <node CREATED="1193392767389" ID="Freemind_Link_1901080961" MODIFIED="1193392777035" TEXT="GUI Callback"/>
-<node CREATED="1193392777503" ID="Freemind_Link_130622541" MODIFIED="1193392788820" TEXT="Exceptions wile restore"/>
+<node CREATED="1193392777503" ID="Freemind_Link_130622541" MODIFIED="1193392788820" TEXT="Exceptions while restore"/>
 </node>
 </node>
 </map>

src/Gui/Application.h

@@ -223,7 +223,7 @@ public:
 
     /** @name Init, Destruct an Access methods */
     //@{
-    /// some kind of singelton
+    /// some kind of singleton
     static Application* Instance;
     static void initApplication(void);
     static void initTypes(void);