Add QRGen lib dependency.
Save 2 sample QR codes for the web link: 'http://google.com'

- same QR data, only PNG image size difference.
QRCode generator implementation.
Initial cut of integrating QRCode image into Plan domain.

- clean-up various setters, and centralise plan <-> selection bidirectionals.
Support for Base64 Encoded QR Code image.
Assert Base64 Encode-Decode Symmetry.
Centralise bidirectional relationship addition account <-> plan.
Temporarily @Ignore'd tests.