Misc. typos

Found via `codespell` 
+ removed rtengine/dcraw.patch per discussion in https://github.com/Beep6581/RawTherapee/pull/4395

rtgui/filepanel.cc

@@ -411,7 +411,7 @@ bool FilePanel::handleShortcutKey (GdkEventKey* event)
 
 void FilePanel::loadingThumbs(Glib::ustring str, double rate)
 {
-    GThreadLock lock; // All GUI acces from idle_add callbacks or separate thread HAVE to be protected
+    GThreadLock lock; // All GUI access from idle_add callbacks or separate thread HAVE to be protected
 
     if( !str.empty()) {
         parent->setProgressStr(str);