Details:
- Moved miscellaneous language-related definitions, including defs
related to the handling of the 'restrict' keyword, from the top half
of bli_macro_defs.h into a new file, bli_lang_defs.h, which is now
#included immediately after "bli_system.h" in blis.h. This change is
an attempt to fix a report of recent breakage of C++ compilers due
to the recent introduction of 'restrict' in bli_type_defs.h (which
previously was being included *before* bli_macro_defs.h and its
restrict handling therein. Thanks to Ivan Korostelev for reporting
this issue in #527.
- CREDITS file update.