Generalize the ILP64 BLAS/LAPACK symbol name handling to deal with
arbitrary prefix/suffix.

The build-time behavior is changed so that HAVE_BLAS_ILP64 and
BLAS_SYMBOL_SUFFIX/PREFIX defines are added to compile options
as appropriate.

Mainly to make autodetection of BLAS/LAPACK easier for downstream
numpy.distutils users, add get_info aliases 'blas_ilp64_opt',
'blas_ilp64_plain_opt', and 'blas64__opt' for any/no/""&"64_"
prefix&suffix, and the same for lapack. (Due to the way system_info
works, each also gets a separate class.)

In addition to openblas64_ which has a fixed suffix, add the (by default
suffixless) openblas_ilp64, which correspond to the most likely cases to
be present.

This is an emerging "standard" for 64-bit BLAS/LAPACK, avoiding symbol
clashes with 32-bit BLAS/LAPACK, originally introduced for Julia.
OpenBLAS can be compiled with 64-bit integer size and symbol suffix
'64_' (INTERFACE64=1 SYMBOLSUFFIX=64_).  OpenBLAS built with this
setting is also provided by some Linux distributions (e.g. Fedora's
64-bit openblas packages).

Now libflame may be used as a LAPACK back-end.
libflame requires an external BLAS so one has to
also have this enabled.
Also added release notes for NPY_*_ORDER and libFLAME.

* BLD: use libraries as a key consistently in all site.cfg sections

BUG: parse shell escaping in extra_compile_args and extra_link_args