helper::BytesFactor / parsing

[germasch]

The code that takes the string for initial / max buffer size and parses it to a number doesn't handle bytes. It's also replicated 4 times across BP3/BP4, so since there is already a helper, why not consolidate the entire thing, and do it right?.

BytesFactor understands the suffixes "kb", "mb", "gb", and "b"/"bytes". However the parsing code that calls it assumes that the suffix is exactly two characters always, so "b"/"bytes" will never be understood.

There is helper::EndsWith -- this sounds like a good use for it. It supports case-insensitive match, which would make it understand "GB" etc as well. Finally, why not support a plain number, too? That's what tripped me up originally, I though just saying "1024" should work.

By the way, this is clearly a low priority item.