Commit of qrcode encoder and supporting modules.

Includes demo module with basic png and crypto
for a full-cyle demo with a mobile phone.

README.markdown

@@ -0,0 +1,29 @@
+git remote add origin git@github.com:komone/qrcode.git
+  git push -u origin master
+
+QR Code Encoder
+===============
+
+Reference used was ISO/IEC 18004, 1st Edition (2000)
+
+This implementation is informed by my specific needs, i.e. to provide
+two-factor authentication for mobile phones running Google Authenticator.
+
++ "Byte" mode only (don't need e.g. numeric mode or kanji mode).
++ Encode only (no detection/decode).
++ Basic supporting library functions provided (HOTP, PNG image functions) to allow full-cyle demo.
+
+Demo
+====
+
+1. Download repo and compile with `erl -make`
+2. Install Google Authenticator App on your mobile:
+	+ iPhone:  http://itunes.apple.com/us/app/google-authenticator/id388497605?mt=8
+	+ Android: https://market.android.com/details?id=com.google.android.apps.authenticator
+3. Run demo: `qrcode_demo:run().`
+4. Open the generated `qrcode.png` file
+5. Scan the qrcode into the phone.
+6. Ensure server clock is correct.
+7. The value of `qrcode_demo:totp()` should show the same passcode as the phone.
+
+NOTE: This documentation is rather basic as this was open-sourced by specific request!