- use traits in rewindinputstream, alternative wrappers for char/string
  traits depending on underlying io stream
- spooling in RIS:
  - thread-safe tempnames
  - Windows, respect environment variables like TEMP
- module loader
  - use weak pointers to create objects (pointers which don't transfer
    ownership but act more as a handle). Avoid funny trouble with
    objects originating for modules (especially DLLs on Windows)
  - ctor parameter types must be part of register function signature
- type detection
  - content based type detection on Windows
    - port of libmagic?
    - something from Microsoft (around the index service)? 
- robots.txt
  - handle Sitemap
- Parse URLs from sitemaps