Extend system hooks table by socket and connect functions.

2011-02-02 Marcus Brinkmann <marcus.brinkmann@ruhr-uni-bochum.de>

• assuan-defs.h (_assuan_socket, _assuan_connect): New prototypes.
• assuan.h.in (ASSUAN_SYSTEM_HOOKS_VERSION): Bumped to 2. (struct assuan_system_hooks): Add socket and connect members. (assuan_socket, assuan_connect): New prototypes. (_ASSUAN_SYSTEM_PTH_IMPL): Add socket and connect members. * assuan-socket-connect.c (assuan_socket_connect): Call _assuan_socket and _assuan_connect instead _assuan_sock_new and _assuan_sock_connect.

(libassuan.def, libassuan.vers): Add assuan_socket and
assuan_connect.

• system.c (_assuan_system_hooks_copy): Initialize destination from system hooks, so we don't get any NULL pointers if there is a version mismatch. Support version 2 of the system hook structure. (_assuan_socket, _assuan_connect): New functions.
• system-posix.c (assuan_socket, assuan_connect): New functions. (_assuan_system_hooks): Add assuan_socketm, assuan_connect.
• system-w32.c (assuan_socket, assuan_connect): New functions. (_assuan_system_hooks): Add assuan_socketm, assuan_connect.
• system-w32ce.c (assuan_socket, assuan_connect): New functions. (_assuan_system_hooks): Add assuan_socketm, assuan_connect.