Relies on libqrencode, cloned and compiled by cmake

Tuleap: #616
Change-Id: I2cb9281289478321751a947fc8828bf0ba5c6f27

This commits brings optionnal linking against Sparkle framework.
This framework is used to autoupdate apps not present in the Mac app store

Refs #75349

Change-Id: I82b14757c106f1282d91e631927057d00989feb7