Ignore example executables.

Stop these clutting the `git status` output.

Signed-off-by: Mark Harris <mark.hsj@gmail.com>

.gitignore

@@ -36,6 +36,11 @@ vorbisfile-uninstalled.pc
 vorbisfile.pc
 doc/Doxyfile
 doc/doxygen-build.stamp
+examples/chaining_example
+examples/decoder_example
+examples/encoder_example
+examples/seeking_example
+examples/vorbisfile_example
 lib/test_sharedbook
 test/test