enables pltcl unknown support.


Also it adds substituting of tclsh with tclsh that was by configure in
pltcl_*mod scripts. For example, On freebsd, tclsh can be called
tclsh8.2 or
tclsh8.3 depending on installed version of Tcl.

After patching files
  src/pl/tcl/modules/pltcl_listmod
  src/pl/tcl/modules/pltcl_loadmod
  src/pl/tcl/modules/pltcl_delmod
must be renamed(copied,repocopied) to
  src/pl/tcl/modules/pltcl_listmod.in
  src/pl/tcl/modules/pltcl_loadmod.in
  src/pl/tcl/modules/pltcl_delmod.in

seva@sevasoft.kiev.ua