Remove ChannelHandlerEvent struct, which has never been used in all of
recorded Tcl history.
Still need to purge comments of mentions of ChannelHandlerEventProc()
which is similarly pre-historic.
[ccc2c2cc98]: lreplace edge case
Make corrections to long-false comments.
Remove unused macros.
Updating to the latest trunk
New build process for Tcl kits in Unix (Windows port to follow...)

Rather than force a "make install" to build the vfs, the tclkit now
performs it's own "install" to a subdirectory (using destdir) to collect
the files it needs for its vfs.

tclkits no longer link to the tcl library. Instead, all of the obj files that
are used to assemble the lib are instead packed into the executable. Thus,
"make tclkit" produces the tclkit. That's it. No dlls. No tclsh. Makes no
other mark on the file system save the bare essentials it needs. It uses the
same variables in the makefile as the tcl libraries, so as they are updated
so too is tclkit.

Zlib files are *always* build for tclkits. Tclkits can never rely on the
presence of zlib on the systems in which they will be installed.