optional version of sharing buttons

There is a way to enable social sharing without hurting user's security (if it would be hurt anyway) and privacy.
The idea is to show picture instead of loading social buttons, and only load real social buttons if user wants to do so. Users who don't wont to share the site won't load any external JS file.

This idea was proposed and discussed before:
here: https://stackoverflow.com/questions/7187673/like-button-and-privacy-concern
and here: http://yro.slashdot.org/story/11/09/03/0115241/Heises-Two-Clicks-For-More-Privacy-vs-Facebook

I've added following limitations:
- Sharing can be enabled only if user is online - it's hidden otherwise.
- Once user enables sharing, sharing buttons will be removed if user:
  - clicks on 'Click to Generate Addresses' button,
  - changes number of addresses he'd like to generate, or
  - navigates to 'about' page.

:)