Configuration option for opening links from popup in current tab

[yermulnik]

Based on conversation in #286 could you please consider adding a configurable option for Update Scanner to either open links from popup in new tab or in the current tab

Steps to reproduce the problem:

Click the link in popup

What you expected to happen:

Clicking on link in popup to replace current tab content or to open new tab based on configuration option value

What actually happened:

Clicking on link in popup opens new tab