[TCLCORE] updated TEA 3.0 spec for testing

[Jeff H. <jeffh@ActiveState.com>]

I have revamped the sample extension to use a new TEA spec that
has several changes.  The key ones are:

* It no longer uses special makefile-isms that busted old unix
systems still can't handle (like IRIX).

* You specify the source files in the configure.in (using a simple
ac macro), so trickiness with EXTRA_SOURCES, handling of cpp files
and the like is alleviated.

* Uses a few more ac 2.5x bits for better warnings.

* TEA_INIT is now versioned.

The full ChangeLog entry is:

* configure:           Update of TEA spec to (hopefully) simplify
* configure.in:        some aspects of TEA by making use of more
* Makefile.in:         AC 2.5x features.  Use PACKAGE_NAME (instead
* generic/tclsample.c: of PACKAGE) and PACKAGE_VERSION (instead of
* tclconfig/tcl.m4:    VERSION) arguments to AC_INIT as the TEA
package name and version.
Provide a version argument to TEA_INIT - starting with 3.0.
Drop all use of interior shell substs that older makefiles didn't
like.  Use PKG_* naming convention instead.
Move specification of source files and public headers into
configure.in with TEA_ADD_SOURCES and TEA_ADD_HEADERS.  These will
be munged during ./configure into the right obj file names (no
$(SOURCES:.c=.obj) needed).
There is almost nothing that should be touched in Makefile.in now
for the developer.  May want to add a TEA_ADD_TCL_SOURCES for the
RUNTIME_SOURCES that remains.
Use SHLID_LD_FLAGS (instead of SHLID_LDFLAGS) as Tcl does.
Only specify the user requested LDFLAGS/CFLAGS in the Makefile,
don't mention the _OPTIMIZE/_DEBUG variants.

I have tested this on a variety of platforms, but I'd like to know
what others think of the changes (if anything is broken or still
doesn't work on platforms I don't have).  I tested:

* Windows
* Windows/CE
* Linux
* Solaris (32 and 64 bit)
* AIX-4.3 (32 and 64 bit)
* HP-11 (32 and 64 bit)

Note that unlike many earlier updates to tclconfig/tcl.m4, this is
not a drop-in replacement to other TEA packages.  They will need to
update both their Makefile.in and configure.in accordingly.

  Jeff Hobbs, The Tcl Guy
  http://www.ActiveState.com/, a division of Sophos