Quill updates require blocks automatically.

If a pkgModules.tcl file marks its "package requires" properly, then
they will be updated automatically to the versions listed in
project.quill.
version validate

Added version.tcl to quillapp(n).  "version validate" validated package
provide version strings.
Added project.quill validation

As part of this, added "prepare" to quillapp/misc.tcl and the
quillapp/version.tcl validation type ensemble.
quill(5) includes validation requirements

The validation requires for project names, etc., are no explicit in the
quill(5) man page.
project.quill is parsed in a smartinterp.
quill(5): Implemented full "app" syntax

The project.quill "app" statement is now consistent with the quill(5)
manpage.
Simplified bin/quill.tcl

Simplified the content of bin/quill.tcl.  In particular, the "main"
procedure was moved to quillapp/main.tcl.
quill new app creates main.tcl

The "quill new app" command now uses a simplified "$app.tcl" and puts
the main routine in lib/fooapp/main.tcl.  This is the only package file
created by default for the app.
Added loader script code to load Tk

As part of this, updated quillinfo(n) so that the user can query
whether a given app is a GUI or not.
Updated TODO