loader: new module with package.loaders functions.

* lib/larch/loader.lua: New file. Functions that can be added to
`package.loaders` to expand macros automatically.
* local.mk (EXTRA_DIST): Add lib/larch/loader.lua.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
maint: add relevant summary and description text to rockspecs.

* rockspec.conf (description.summary, description.detailed): Use
relevant text in here!

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
doc: move manual page to man/man1.

* local.mk (doc/larch.1): Rename from this...
(man/man1/larch.1): ...to this.
(EXTRA_DIST): Adjust.
* rockspec.conf (build.copy_directories): Remove `doc`; add `man`.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
refactor: make larch reentrant.

* lib/main.lua: Return a "Main" typed std.object with an execute
method, as required for Specl 11 inprocess tests.
(execute): Move processing code to this new function.
* local.mk (bin/larch): Change evaluate argument to call the Main
object, and exit with the returned status.
* bin/larch: Regenerate.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
refactor: move larch main.lua into lib/larch.

* lib/main.lua: Move from here...
* lib/larch/main.lua: ...to here.
* local.mk (dist_noinst_DATA): Adjust.
(bin/larch): require 'larch.main' rather than 'main'.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
slingshot: bump luarocks requirement to luarocks-2.1.2.

* slingshot: Update to latest master.
* .gitmodules: New file, now that slingshot is a full submodule.
* .travis.yml: Regenerate from lastest slingshot.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: remove unused gnulib submodule.

* .gitmodules (gnulib): Remove.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
configury: git ignore generated man directory.

* .gitignore: Add /man.

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