Support in the Tcl core

There are two ways we could support TEKI in the Tcl core.
One is to include the installer interface (as an auto_laod file),
the other is to include just the support needed to setup Teki
packages.

When Teki installs a package, it creates a pkgIndex.tcl file
for the package.  The pkgIndex.tcl
files set entries in the global array tclPkgInfo -- this
array contains information about all the packages available.
After setting values in tclPkgInfo, the TclPkgInit function
is called with a single argument, the package id (e.g., dp4.0).
This id is used to index into the tclPkgInfo array.

TclPkgInit looks at tcl_platform(os) and tcl_platform(osVersion)
to determine what files, if any, should be loaded when a
package require is issued.  Assuming that the package has been
installed for the run-time architecture, TekiPkgInit will
call package ifneeded, announcing the availability of the package.

When a package require is issued for a Teki package, the 
TekiPkgSetup function is called with the package id and the
system name (e.g., "solaris").  TekiPkgSetup loads and sources
the appropriate package files for the architecture.

These two functions, TekiPackageInit and TekiPackageSetup, 
should go in the core.  They're in teki.tcl, towards the bottom
of the file.

BTW, is there a reason why the core doesn't source the pkgIndex.tcl
files on initialization?  It doesn't right now, which means the
first time you run "package names", you only see Tcl and Tk,
regardless of the number of packages installed.  However, once
the package unknown procedure is called, all the package names
appear, whether they've been loaded or not.  Seems strange to me.

One other little bug that may have already been fixed.
The auto_path under windows gets set to the 4 element list

   {C:/Program Files/TCL/lib/tcl7.6}
   C:/Program
   Files/TCL/lib
   C:/PROGRA~1/TCL/lib/tk4.2

if you install Tcl in C:\Program Files\Tcl.  The space
in tcl_pkgPath (= "C:/Program Files/TCL/lib") is fooling it,
I think tcl_pkgPath should be set to {{C:/Program Files/TCL/lib}},
(i.e., a list with one element), right?   This bug makes a mess
of loading packages under Windows...


