[plt-scheme] Why PLT-206 doesn't have libraries on Win32

The 205 distribution had import libraries lib/msvc/libmzsch205_000.lib and
lib/msvc/libmzgc205_000.lib.
But 206 don't. Although it isn't serious, I think, that having line about it
in release notes will be great idea.
Also mzc tries to use libmzgcxxxxxxx.lib and libmzschxxxxxxx.lib instead of
libmzYYY206_000.lib


-- 
Sergey Khorev
Jimmy Carter says the GOP Convention was "a debacle." That's French
for Trust Me.
 -- National Review