larch: sync with upstream, and simplify callers.

Richer `from` syntax encourages simpler symbol import blocks at
the start of modules.
* lib/larch/from.lua: Sync with upstream.
* lib/specl/formatter/progress.lua,
lib/specl/formatter/report.lua, lib/specl/formatter/tap.lua,
lib/specl/inprocess.lua, lib/specl/loader.lua, lib/specl/main.lua,
lib/specl/matchers.lua, lib/specl/runner.lua, lib/specl/shell.lua,
lib/specl/util.lua: Simplify accordingly.

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