lang/algol68g: update Algol 68 Genie to version 3.0.6, hook the tests

This new release is mostly the result of the evolution of the previous
version over the [five] years.  Since the hardware representation of
several modes has changed, the version number has been incremented.

Former Algol 68 Genie versions 1 and 2 implement 32-bit INT, BITS and
64-bit REAL modes, while implementing all LONG and LONG LONG modes in
software.  Version 3 implements 64-bit INT, REAL and BITS modes, and
128-bit LONG modes which are supported by modern processors; only LONG
LONG modes remain implemented in software.

Version 3.0 offers bindings for more functions from the GNU Scientific
Library, as well as for statistical routines from the GNU R stand-alone
mathematics library, and adds a generalized incomplete gamma function
according a recent algorithm by Abergel and Moisan from the University
of Paris.  Also, it incorporates reported bugfixes.

While here, drop CONFIGURE_ARGS+=--enable-compiler as it is enabled by
default, and switch to dedicated pkg-plist now that there are 36 files.