Bug in current runtime.kit

Hello,

The runtime kits for 8.4.18 and 8.5.1 (as found on 
http://www.equi4.com/pub/tk/tars/) have an error in Tk's pkgIndex.tcl file.
The package tries to load a "dylib" i.e. a Mac dynamic library.

The following fixes the problem:

Unwrap runtime.kit (analogous for runtime85.kit):
tclkit sdx.kit unwrap runtime.kit

Edit runtime.vfs/lib/tk8.4/pkgIndex.tcl:

Change second line:
package ifneeded Tk 8.4 [list load [file join $dir .. libtk8.4.dylib] Tk]

To:
package ifneeded Tk 8.4 [list load [file join $dir libtk8.4[info 
sharedlibextension]] Tk]

Wrap the Kit again:
tclkit sdx.kit wrap runtime.kit

Now the generated TclKit is able to correctly "package require Tk" on 
non-Mac platforms.

Greetings,

Paul