maint: call woger properly at release time.

* GNUmakefile (WOGER_ENV): Lua environment settings for extracting
woger release variables.
(WOGER_OUT): Lua call for feretting out the rockspec file
settings used by woger.
(release): Fully populate all the fields needed to make a correct
woger release of Specl.

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