* iface/gspn/gspn.cc, iface/gspn/gspn.hh: New files. * iface/gspn/Makefile.am (libspotgspn_la_SOURCES): Add them.
[__cplusplus]: Wrap everything under extern "C".
* iface/Makefile.am, iface/gspn/Makefile.am: New files. * Makefile.am (SUBDIRS): Add iface. * iface/gspn/gspnlib.h: New file, from Yann and Souheib.