Cleanup: reorganize doxygen modules

- Nest compositor pages under the compositor module
- Nest GUI, DNA/RNA & externformats modules under Blender.
- Remove modules from intern which no longer exist.
- Add intern modules (atomic, eigen, glew-mx, libc_compat, locale,
  numaapi, rigidbody, sky, utfconv).
- Use 'intern_' prefix for intern modules since some of the modules
  use generic terms such as locale & atomic.

intern/guardedalloc/MEM_guardedalloc.h

@@ -18,7 +18,7 @@
  */
 
 /** \file
- * \ingroup MEM
+ * \ingroup intern_mem
  *
  * \brief Read \ref MEMPage
  *

intern/guardedalloc/cpp/mallocn.cpp

@@ -15,7 +15,7 @@
  */
 
 /** \file
- * \ingroup MEM
+ * \ingroup intern_mem
  */
 
 #include "../MEM_guardedalloc.h"

intern/guardedalloc/intern/leak_detector.cc

@@ -15,7 +15,7 @@
  */
 
 /** \file
- * \ingroup MEM
+ * \ingroup intern_mem
  */
 
 #include <cstdio> /* Needed for `printf` on WIN32/APPLE. */

intern/guardedalloc/intern/mallocn.c

@@ -15,7 +15,7 @@
  */
 
 /** \file
- * \ingroup MEM
+ * \ingroup intern_mem
  *
  * Guarded memory allocation, and boundary-write detection.
  */

intern/guardedalloc/intern/mallocn_guarded_impl.c

@@ -18,7 +18,7 @@
  */
 
 /** \file
- * \ingroup MEM
+ * \ingroup intern_mem
  *
  * Guarded memory allocation, and boundary-write detection.
  */

intern/guardedalloc/intern/mallocn_inline.h

@@ -27,7 +27,7 @@
  */
 
 /** \file
- * \ingroup MEM
+ * \ingroup intern_mem
  */
 
 #ifndef __MALLOCN_INLINE_H__

intern/guardedalloc/intern/mallocn_intern.h

@@ -18,7 +18,7 @@
  */
 
 /** \file
- * \ingroup MEM
+ * \ingroup intern_mem
  */
 
 #ifndef __MALLOCN_INTERN_H__

intern/guardedalloc/intern/mallocn_lockfree_impl.c

@@ -15,7 +15,7 @@
  */
 
 /** \file
- * \ingroup MEM
+ * \ingroup intern_mem
  *
  * Memory allocation which keeps track on allocated memory counters
  */