Improve documentation: Some words about multiple execution contexts in lwIP

src/api/api_lib.c

@@ -3,7 +3,7 @@
  * Sequential API External module
  * 
  * @defgroup netconn Netconn API
- * @ingroup threadsafe_api
+ * @ingroup sequential_api
  * Thread-safe, to be called from non-TCPIP threads only.
  * TX/RX handling based on @ref netbuf (containing @ref pbuf)
  * to avoid copying data around.

src/api/netifapi.c

@@ -3,7 +3,7 @@
  * Network Interface Sequential API module
  *
  * @defgroup netifapi NETIF API
- * @ingroup threadsafe_api
+ * @ingroup sequential_api
  * Thread-safe functions to be called from non-TCPIP threads
  * 
  * @defgroup netifapi_netif NETIF related

src/api/sockets.c

@@ -3,7 +3,7 @@
  * Sockets BSD-Like API module
  *
  * @defgroup socket Socket API
- * @ingroup threadsafe_api
+ * @ingroup sequential_api
  * BSD-style socket API.\n
  * Thread-safe, to be called from non-TCPIP threads only.\n
  * Can be activated by defining @ref LWIP_SOCKET to 1.\n