Bump to version 0.22

0.22:

• zbarcam-qt: allow changing resolutions in real time
• zbarcam-qt: better support ZBar options
• zbarcam-qt: do several visual improvements
• zbarcam-qt: make it remember the geometry
• zbarcam-qt: allow show/hide control and options bars
• zbarcam-qt: remember lastly used settings and camera controls
• zbarcam-qt: allow changing ZBar decode options via GUI
• Add API to allow get/set resolutions
• img_scanner: add handler for color-inverted codes
• img_scanner: fix get_config parameter validation
• scan_video: improve logic to remove duplicated/invalid devnodes
• symbol.c: fix symbol hash logic (prevents crash with QR options)
• configure.ac: fix an error at libv4l2 package check
• fix some typos
• exit gracefully when decoding split QR codes