[Tclplugin-core] Updated makefile with build/install instructions

[Jeff H. <je...@Ac...>]

I have updated the CVS with much better build and install instructions,
as well as a fully working 'make install' (should you configure correctly).

I have also commited a precompiled win/pluginhostctrl.dll for those that
want to test against IE.  They just have to regsrv32 this dll and then
you will have NPAPI plugins in IE again.

There is a known issue with focus in Mozilla on Linux (maybe *nix).

  Jeff Hobbs                     The Tcl Guy
  Senior Developer               http://www.ActiveState.com/
      Tcl Support and Productivity Solutions