Maintenance/Feature: One URL can open multiple windows after clicking multiple times

[qwertyuiopzxcvbnmlkjhgfdsa1]

When click on URL, Junction works correctly, opens window with Browsers, where user can choose, where open URL.

Issue: When clicking for example 4x times, 4 windows are opened.

Fix:
1,When clicking on URL and window with this URL is already opened, second(third,..) window shouldn't be opened.
2,Bonus(possible?) -Also currently opened window with current url, after click:
a) should go to Top view
b) center it in the middle of the screen
c) blink several times(for example edges could blink)

[sonnyp]

see #99 (comment)