Adding ipc_ prefix to ipc primitives

* Also change _orig to _intr for clarity
 * Cleaned up {IPC,KER}VEC
 * Renamed _minix_kernel_info_struct to get_minix_kerninfo
 * Merged _senda.S into _ipc.S
 * Moved into separate files get_minix_kerninfo and _do_kernel_call
 * Adapted do_kernel_call to follow same _ convention as ipc functions
 * Drop patches in libc/net/send.c and libc/include/namespace.h

Change-Id: If4ea21ecb65435170d7d87de6c826328e84c18d0

drivers/readclock/readclock.c

@@ -120,9 +120,9 @@ main(int argc, char **argv)
 
 		log_debug(&log, "Sending Reply");
 
-		r = sendnb(caller, &m);
+		r = ipc_sendnb(caller, &m);
 		if (r != OK) {
-			log_warn(&log, "sendnb() failed\n");
+			log_warn(&log, "ipc_sendnb() failed\n");
 			continue;
 		}
 	}