Added QRCode dependency.
Implemented QR codes in png.
Applied PR for SVG QR codes.

https://github.com/davidshimjs/qrcodejs/pull/23
Replaced canvas by svg qr codes.
Removed angualar-qrcode dependency.
minor fixes in send view
Make contact addresses editable.

Contacts are stored in an array now.
scaling the SVG qr codes
Ordered contacts alphabetically.
Applied PR for background in SVG QR codes.

https://github.com/davidshimjs/qrcodejs/pull/24
Applied QR directly instead of template an svg.
Rework updating contacts.
remove unused line
Improve backend logs and remove preloading of the keyring in the backend wallet service (its already loaded).
Merge branch 'develop' of https://github.com/darkwallet/darkwallet into develop
Maintain the identicon when contact editing form is opened.
making QR codes more readable
Improve log reporting on the frontend and allow disconnecting channel callbacks when controller goes away.
Merge branch 'develop' of https://github.com/darkwallet/darkwallet into develop
Factor channel linking functionality into ChannelLink class, this allows connecting a communications channel to a controller.