maint: install rockspec with module rule.

By renaming any non-lua files with a .lua extension, we can avoid
running configure or make install, and use LuaRocks module list
to copy the prebuilt files into place.  This also allows removing
the last barrier to being fully relocatable.
* lib/zmacs/default-bindings.el: Rename from this...
* lib/zmacs/default-bindings-el.lua: ...to this.
* lib/zmacs/keymaps.lua (init_default_bindings): Adjust.
* lib/zmacs/zmacs.mk (dist_zmacsdata_DATA): Likewise.
* lib/zmacs/zmacs.in (PATH_DOCDIR): Remove.
* local.mk (mkrockspecs_args): Switch to LuaRocks module build.
* rockspec.conf (copy_directories): Remove docs.
* slingshot: Sync with upstream for sorted rockspec module list
* lib/zmacs/zmacs.mk (zmacsdocdatadir): Install location for doc
resource files.
(dist_zmacsdocdata_DATA): Resources to generate, and a rule to
generate from the raw text files they represent.
(EXTRA_DIST): Add lib/zmacs/command.lua.
(DISTCLEANFILES): Move lib/zmacs/commands.lua from here...
(MAINTAINERCLEANFILES): ...to here.
Add the generated doc resources.
* lib/zmacs/commands/help.zl (describe-copying)
(describe-no-warranty, view-emacs-FAQ): New interactive functions
for fetching and displaying help resources.
* lib/zmacs/default-bindings-el.lua: Bind \C-h and F1 keymaps to
the new functions.
* lib/zile/version.lua.in (M.COPYRIGHT_NOTICE): Update to mention
new help key-chords.
* lib/zmacs/main.lua (splash_str): Likewise.
* .gitignore: Add lib/zmacs/doc.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
zmacs: distribute all luarocks install files.

* lib/zmacs/zmacs.in: Move from here...
* bin/zmacs: ...to here.  Remove all configure substitutions.
Dynamically search for a suitable Lua binary and re-execute.
* lib/zmacs/zmacs.in: A new wrapper script to set local LUA_PATH
directories so that zmacs can be run from the build tree.
* configure.ac (AC_CONFIG_FILES): Generate lib/zmacs/zmacs.
* local.mk, lib/zmacs/zmacs.mk: Simplify accordingly.

* .gitignore: Adjust.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: make sure to always use the zmacs wrapper in-tree.

* lib/zmacs/help2man-wrapper: Call the zmacs wrapper.
* lib/zmacs/zmacs.mk: Likewise.
Avoid breaking VPATH builds while we're here.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>