http://zzz.i2p/topics/2274

    - Support readonly blockfiles
    - Open blockfile readonly if not in router context
    - Log warning if blockfile is locked

- Automatic corruption repair in blockfile
- Automatic removal of bad entries in BFNS
- Use unsigned shorts to extend max lengths to 65535
- Check max length
- Throw IOE on negative ints
- Tweak fromProperties() exceptions
- Fix DataHelper encoding issues (ticket #436)
- CSS tweaks