Make etags.sh executable
VL (with Jared): add scopestack abstraction for looking up various kinds of things, and use that in various transforms
Merge branch 'master' into scopestack
vl -- porting more transforms to use scopestacks
scopestack work
more work on scopestacks
fix up a few remaining things broken by scopestack stuff
Improve cert.pl support for provisional certification in the presence
of other, non-provisionally-certified files.  In books/GNUMakefile,
remove the special cases for the two directories that use it.
Move a set-inhibit-warnings form from the top of doc.lisp into doc.acl2, allowing it to certify faster by skipping most of the second pass.
fix more breakage
VL: Add tools for looking up variables, definitions, etc. in nested
namespaces (mlib/scopestack.lisp).  Change some existing transforms to
use them.
Added :doc git-quick-start.  Updated :doc community-books for github.  Added static-hons support for GCL.  Use compiled memoized functions during include-book.  For Lisps that don't always compile, memoize only compiles when existing function is compiled.

:Doc note-7-0 has a link to new topic git-quick-start, and also says:

  Static honsing for ACL2(h), an efficiency enhancement formerly only
  available for CCL, is now incorporated into builds on sufficiently
  recent GCL versions.

  ACL2(h) could fail to use previously-compiled definitions for
  [memoize]d functions when [include-book] is invoked. This has been
  fixed.

  (For ACL2(h), and irrelevant for CCL and SBCL) Calls of [memoize]
  only compile the memoized definition when the original function is
  compiled, rather than unconditionally as before.

Also fixed a small bug in :doc note-7-0: @(tsee pbt!) should have been
@(tsee pcb!), and now it is.

NOTE regarding the new :doc topic, git-quick-start, in
books/system/doc/acl2-doc.lisp: I suspect that the pairs of
fetch/merge commands can be replaced by a suitable pull command.  If
anyone is SURE about that, I hope that person will make that change.
Merge remote-tracking branch 'remotes/origin/master'
Merge remote-tracking branch 'remotes/origin/master'
Added Jared's code for fancy-string-reader, which for example may later prove useful when writing Latex.

The fancy-string-reader mentioned above still needs documentation, but
Jared's book mentioned here in :doc note-7-0, added with his
permission (as is the code itself), helps in understanding it:

  A new reader macro, #{"""..."""}, has been contributed by Jared Davis
  to support the writing of strings without escape characters. See
  his community book books/system/fancy-string-reader-test.lisp for
  examples.

Fixed, I hope, :doc git-quick-start to explain what to do when the
merge fails.
Brought doc.lisp up-to-date with books/system/doc/acl2-doc.lisp.
Fixed bug specific to ACL2 (not ACL2(h)) that I introduced earlier today.
Add subsection of books-certification xdoc on how to certify books manually.
VL add a scopestack feature, and fix a fast alist problem in unparameterize
(GCL CLtL1 only) Fixed a bug that was preventing [set-debugger-enable] from taking effect in non-ANSI GCL.