QuotedPrintable codec refactoring

[Oleg Kalnichevski]

Folks

I am currently working on refactoring QuotedPrintable codecs to address 
MIME4J-103 and MIME4J-143. I also would like to look into possibility of 
eliminating intermediate content buffering in Base64InputStream and 
removal of ByteQueue and UnboundedFifoByteBuffer classes

If I hear no objections, I'll be committing my changes directly to the 
trunk. Please complain loudly if that is not ok. If you prefer 
review-then-commit approach I could commit my changes to a private 
branch first.

Oleg