Address several issues from compiling examples

Compiling the code from examples "code-block:: c" along with public
includes and a bsp exposed a few issues amongst a lot of false
positives. Address some of these:

* Terminate struct declarations with ';'. Mainly for pedantic
  correctness.

* Show ptrdiff_t instead of size_t for the sbrk() prototype, matching
  the current argument type in rtems.

* Replace some occurrences of unsigned16 with uint16_t.

* Fix odd type declaration, "uint8_t char*" -> "char*".

* Use appropriate helper to get chain head instead of invalid access to
  nonexistent struct member.

* Remove several excess '\' escapes.

* Use RTEMS_SELF instead of undefined SELF.

* Use rtems_task instead of void for task functions.

* Add missing stack size parameter in task creation.

* Use rtems_interrupt_level instead of undefined rtems_interrupt.

* Correct return value format for rtems_object_id_get_api()
  rtems_object_id_get_index() (enum and uint16_t) and also fix
  corresponding print formatting.

* Correct return value documentation for rtems_object_id_get_class(),
  rtems_object_id_get_node() and rtems_object_id_get_index()
  int -> uint32_t.

* Use RTEMS_SUCCESSFUL instead of undefined RTEMS_STATUS_SUCCESSFUL and
  fix return value variable name in rate monotonic examples.

* Use RTEMS_TIMEOUT instead of undefined TIMEOUT and RTEMS_PERIOD_STATUS
  instead of undefined STATUS.

* Add missing fields to ftpd configuration.

* Correct parameter types in ftpd hook prototype,
  unsigned char * -> void *.

* Fix various code-block:: attributes, c -> makefile and c -> shell.

* Add missing parenthesis in socket buffer memory calculation example.

* Remove typedef in declaration of mq_attr since it is defiend without
  typedef in reality.

* Update siginfo_t declaration to match current reality.

* Update shell user command definition example to include mode, uid and
  gid.

networking/network_servers.rst

@@ -60,7 +60,13 @@ Example hooks structure and configuration structure folllow.
         40,                     /* FTPD task priority */
         512*1024,               /* Maximum hook 'file' size */
         0,                      /* Use default port */
-        ftp_hooks               /* Local ftp hooks */
+        ftp_hooks,              /* Local ftp hooks */
+        0,                      /* Use / as root */
+        1,                      /* Max. connections */
+        0,                      /* Infinite idle timeout */
+        0,                      /* Read-write access */
+        0,                      /* Ignore login check */
+        true                    /* Say hello */
     };
 
 Specifying 0 for the well-known port causes FTPD to use the UNIX standard FTPD
@@ -75,7 +81,7 @@ The prototype for the ``untar`` hook (and hooks, in general) is:
 
 .. code-block:: c
 
-    int Untar_FromMemory(unsigned char *tar_buf, unsigned long size);
+    int Untar_FromMemory(void *tar_buf, size_t size);
 
 An example FTP transcript which exercises this hook is:
 

networking/networking_driver.rst

@@ -99,14 +99,14 @@ to be compiled with the appropriate flags.  This can be accomplished by adding
 is inside the RTEMS source tree or is built using the RTEMS application
 Makefiles, then adding the following line accomplishes this:
 
-.. code-block:: c
+.. code-block:: makefile
 
     DEFINES += -D__INSIDE_RTEMS_BSD_TCPIP_STACK__
 
 This is equivalent to the following list of definitions.  Early versions of the
 RTEMS BSD network stack required that all of these be defined.
 
-.. code-block:: c
+.. code-block:: makefile
 
     -D_COMPILING_BSD_KERNEL_ -DKERNEL -DINET -DNFS \
       -DDIAGNOSTIC -DBOOTP_COMPAT

networking/using_networking_rtems_app.rst

@@ -14,7 +14,7 @@ Including the required managers
 
 The FreeBSD networking code requires several RTEMS managers in the application:
 
-.. code-block:: c
+.. code-block:: makefile
 
     MANAGERS = io event semaphore
 
@@ -25,7 +25,7 @@ The networking tasks allocate a lot of memory.  For most applications the heap
 should be at least 256 kbytes.  The amount of memory set aside for the heap can
 be adjusted by setting the ``CFLAGS_LD`` definition as shown below:
 
-.. code-block:: c
+.. code-block:: makefile
 
     CFLAGS_LD += -Wl,--defsym -Wl,HeapSize=0x80000
 
@@ -210,7 +210,7 @@ the first two entries in this structure.
 
     .. code-block:: c
 
-        40 * (1024 + sizeof(struct sockaddr_in)
+        40 * (1024 + sizeof(struct sockaddr_in))
 
 ``unsigned long tcp_tx_buf_size``
     This configuration parameter specifies the maximum amount of buffer memory