Use fallthrough attribute.

Use __attribute__ ((fallthrough)) to indicate switch case fall through
instead of a comment. This ensures that the fallthrough warning is not
triggered even if the file is pre-processed (hence stripping the
comments) before it is compiled.

The actual fallback implementation is hidden behind a FALLBACK macro in
case the compiler doesn't support it.

Finally, the -Wimplict-fallthrough warning was upgraded to only allow
the attribute to satisfy it; a comment alone is no longer sufficient.

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
diff --git a/libebl/ChangeLog b/libebl/ChangeLog
index 3b07633..3ecd732 100644
--- a/libebl/ChangeLog
+++ b/libebl/ChangeLog
@@ -1,3 +1,8 @@
+2018-02-09  Joshua Watt  <JPEWhacker@gmail.com>
+
+	* eblobjnote.c (ebl_object_note): Use FALLTHROUGH macro instead of
+	comment.
+
 2017-04-27  Ulf Hermann  <ulf.hermann@qt.io>
 
 	* Makefile.am: Use fpic_CFLAGS.