MGR: Make the flags to InternetReadFileEx() match those of InternetOpen().  Mixed flags can cause unpredictable results.
MGR: if InternetReadFile() sets ERROR_IO_PENDING error, we need to call it again to get the next chunk of data
- client: parse <fetch_on_update> config flag, and show it on startup
MGR: Fix memory leaks, add debug fprintf's trying to find cause of crashes when retrying load of images in notices