spec: rpm-build: decoupled rpm-build-tcl

There's been some discussion on the list as to which rpm-build-*
packages rpm-build should depend on.

The upshot is this:

1) The language should be widely used, and its scripts should
be found in a number of packages not specific to the language
(e.g. packages which do not require %name-devel for build).

2) rpm-build-%name scripts, along with finding dependencies,
should have the effect of syntax check.  This is what makes
them beneficial for all packages, and this is the reason why
rpm-build should pick up such rpm-build-%name package.

Now I think that Tcl fails both points.  Current tcl.req analyzer
simply cannot process Tcl scripts reliably, only Tcl modules.
But Tcl modules are certainly specific to the Tcl language,
and building Tcl modules apparently should involve tcl-devel.
I have just added rpm-build-tcl dependency to tcl-devel.

If too many Tcl packages break because of this change,
which is not likely, I can re-add rpm-build-tcl dependency here.
However, this will also enroll tcl into the base build system.

rpm-4_0.spec

@@ -112,7 +112,7 @@ Requires: tar >= 0:1.13.22-alt1
 Requires: %_bindir/subst
 Requires: rpm-build-perl >= 0.6.2
 Requires: rpm-build-python >= 0.31
-Requires: rpm-build-tcl >= 0.2.1
+Conflicts: rpm-build-tcl <= 0.2
 Conflicts: rpm-build-mono <= 1.0
 
 %package build-topdir