Achim Gratz writes:
> Pushed.

I've found another (and hopefully the last, except for the mostly
dormant gzip code) 16kiB buffer to be increased to 64kiB.  Also, when
installing from a local directory without a setup.ini file there
actually is a need to skip the checksum validation.  For this to work we
also need to record whether we actually set a checksum and testing the
first byte for zero is not correct for doing this.  As detailed in the
design for Bitcoin, there is an exponetnially decreasing probability for
the leading bits to all be zero.  Current Cygwin has more than 80
packages with the first eight bits or more all zero (I've seen 15
leading zero bits in my local mirror).