Add support for user avatars in the core protocol

Add a protocol and the APIs to straightforwardly support user avatars
in client applications. The protocol is designed to transfer avatars
in background, between friends only, and minimize network load by
providing a lightweight avatar notification for local cache validation.
Strict safeguards are imposed to avoid damage from non-cooperative or
malicious users and to limit network usage.

The complete documentation is available in docs/Avatars.md and sample
code is available in testing/test_avatars.c.

Code and documentation are released under the GNU GPLv3 or later, as
described in the file COPYING.

1 files changed, 15 insertions, 0 deletions

diff --git a/testing/Makefile.inc b/testing/Makefile.inc
index 42d89e05..6bb87913 100644
--- a/testing/Makefile.inc
+++ b/testing/Makefile.inc
@@ -105,6 +105,21 @@ tox_shell_LDADD =        $(LIBSODIUM_LDFLAGS) \
                         $(NACL_LIBS) \
                         -lutil
 
+
+noinst_PROGRAMS +=      test_avatars
+
+test_avatars_SOURCES =   ../testing/test_avatars.c
+
+test_avatars_CFLAGS =    $(LIBSODIUM_CFLAGS) \
+                        $(NACL_CFLAGS)
+
+test_avatars_LDADD =    $(LIBSODIUM_LDFLAGS) \
+                        $(NACL_LDFLAGS) \
+                        libtoxcore.la \
+                        $(LIBSODIUM_LIBS) \
+                        $(NACL_OBJECTS) \
+                        $(NACL_LIBS)
+
 endif
 
 EXTRA_DIST +=                   $(top_srcdir)/testing/misc_tools.c