Remove obsolete TODO comments and clarify code

Clean up outdated TODO comments that are no longer relevant and improve comment clarity in activity classes and parsers.

lib/Epub/Epub/parsers/ContentOpfParser.cpp

@@ -150,7 +150,6 @@ void XMLCALL ContentOpfParser::startElement(void* userData, const XML_Char* name
 
   if (self->state == IN_PACKAGE && (strcmp(name, "guide") == 0 || strcmp(name, "opf:guide") == 0)) {
     self->state = IN_GUIDE;
-    // TODO Remove print
     LOG_DBG("COF", "Entering guide state.");
     if (!Storage.openFileForRead("COF", self->cachePath + itemCacheFile, self->tempItemStore)) {
       LOG_ERR("COF", "Couldn't open temp items file for reading. This is probably going to be a fatal error.");