broken commit, commit finished depgraph stuff before smashing hierarchy files
Minor deflist tweaks

  - Deflist now uses define so that you get a signature block.

  - Documentation for automatic deflist events is now split off into a
    foolistp-basics section, underneath your foolistp section.  (Motivation:
    feature any subtopics underneath foolistp more prominently than the deflist
    boilerplate theorems.)

  - Deflist theorems are now presented in a slightly more sensible order.
move some template utilities from vl into tools/templates
vl: shuffle some stuff around with scopestacks & genblobs
broken commit, more hierarchy stuff, prepare to merge with sol
Merge remote-tracking branch 'remotes/solnew/master'

Conflicts:
	books/centaur/vl/mlib/scopestack.lisp
	books/centaur/vl/parsetree.lisp
Minor xdoc tweaks

Arrange so that defxdoc, defsection, and define evaluate the arguments to
:short and :long instead of quoting them.  This may allow you to write
macros that do stuff like:

   `(defsection foo
      :short (cat "blah blah" ,(symbol-name blah-p) "blah blah.")
      ...)

Updated defsection documentation to include a discussion of the recently
added commentary feature, i.e.,

    (defsection foo
      :parents ...
      :short ...
      (defun f (x) ...)
      "<p>The next theorem shows that F is really great.</p>"
      (defthm f-is-the-best ...))

Tweaked defsection so that you can give :extension (foo) instead of just
:extension foo.  (You still can't give :extension (foo bar), but that's
a perfectly sensible restriction.)

Tweaked deflist so that it can create documentation even in the
already-definedp case.

Better error handling on xdoc-extend and xdoc-prepend.

Added a few tests cases.
VL: updates to finding, reordering, hierarchy, and scopestack
Merge
vl -- bugfixes for hierarchy stuff, make function/task parsing more robust
Merge final changes before pushing