toxav renaming: group.{h,c} -> groupav.{h,c}

toxav file for "group" conflicts with toxcore "group" file. While this
works fine in almost all cases, Xcode on macOS is confused with that.

CMakeLists.txt

@@ -225,8 +225,8 @@ if(BUILD_TOXAV)
     toxav/audio.h
     toxav/bwcontroller.c
     toxav/bwcontroller.h
-    toxav/group.c
-    toxav/group.h
+    toxav/groupav.c
+    toxav/groupav.h
     toxav/msi.c
     toxav/msi.h
     toxav/ring_buffer.c

toxav/Makefile.inc

@@ -8,8 +8,8 @@ libtoxav_la_SOURCES = ../toxav/rtp.h \
                     ../toxav/rtp.c \
                     ../toxav/msi.h \
                     ../toxav/msi.c \
-                    ../toxav/group.h \
-                    ../toxav/group.c \
+                    ../toxav/groupav.h \
+                    ../toxav/groupav.c \
                     ../toxav/audio.h \
                     ../toxav/audio.c \
                     ../toxav/video.h \

toxav/groupav.c

@@ -22,7 +22,7 @@
 #include "config.h"
 #endif /* HAVE_CONFIG_H */
 
-#include "group.h"
+#include "groupav.h"
 
 #include "../toxcore/logger.h"
 #include "../toxcore/util.h"

toxav/toxav_old.c

@@ -24,7 +24,7 @@
 
 #include "toxav.h"
 
-#include "group.h"
+#include "groupav.h"
 
 /* Create a new toxav group.
  *