Regression in MK C++, Mk4py, and Mk4tcl

FYI, the following change to MK appears to be faulty:

	2004-09-23    Fix c4_BytesRef::Modify bytes insertion

It shows up in MK's regression test b26, which fails.  There is an 
explanation for why this hasn't been caught before, which I won't go 
into.  It's most unfortunate.

Thanks to Pat Thoyts for reporting the details of this.

If you rely on insertion/mods/deletes of partial data in fields, you 
may want to revert to an earlier CVS checkout, i.e. "cvs ... -D 
2004-09-21 ...".

Several Tclkit builds are affected, probably 8.4.[7-9] and 8.5a2 - 
these have all been built after that time, and may or may not have used 
cvs HEAD then.  If you are worried about potential datafile corruption 
from this, revert to Tclkit 8.4.6 to avoid it.

I've not yet researched what exactly happens, but wanted to get this 
notice out asap.

-jcw