Remove notification permission, as it's no longer needed.

- Remove the annoying notification on updates/installs
- Possibly fix an issue with "Close Tab" showing up in history library

This release should fix most issues that users have been experiencing. Namely:

Page titles may be displayed as the URL of the website instead of the actual title (issue #5 on github)
Tabs getting stuck with title = "Close tab" (also issue #5 on github)

Also possibly fixes:
"Load on all tabs" has to be unchecked then checked again, after first install (issue #4)

Fix github issue #2 by requiring a certain history.length + go forward after back
The required length depends on how the tab was opened (directly (through about:blank) or through about:newtab).
Also makes it automatically press the forward button after (or actually right before) closing the tab, which makes restoration of tabs not lose the BACK_CLOSE state even if it's the last one.

Change naming to include the WE everywhere to make it consistent in the addon manager with the name here on this site.

- Handle redirecting sites better - should work better with opening google results in new tabs now
- Fix most title issues (It still flashes "close tab" shortly, but it should be faster now, never get stuck, and never revert the title to the url as it sometimes did before.)

TL;DR: It should work a lot better now and be more stable.

Detailed changes:
- Fetch script.js on startup so we can modify it
- Inject always, but only push state if needed
- Only spam debugging logs if debug is on
- Run at document_start instead of document_idle
- Increase title switching delay from 10 to 100 ms
- Add a # to the fake history state's url and attempt to remove it after.