Make use of favico an option

@tribut: does this resolve your issue?
Update title with unread count

Further discussion required on a few points:
* show notifications only or unread lines as well?
* only use this when favico is disabled, or indepently?
I welcome all feedback.

Fixes #22
Rework notifications

* Improve content of notifications
  * More descriptive title
  * The bug that caused the need for manually assembling the message has been fixed (#161 or c5e548c8ab41435dd22e7d56089fcec767bdf945)
* Permission for displaying notifications can only be requested upon user interaction in Chrome, not on page load. Bind to connect button
* Take user to g-b tab and buffer causing the notification on click
Fix the confirmation dialog when closing the tab

* Only nag if we're connected
* Set event return value so Chrome shows the dialog
Use ngAnimate to animate sidebar hiding/showing
use alt-g for filter bufferlist

this is more consistent with the other existing shortcuts and is also
the same shortcut go.py recommends in weechat-curses
use consistent format to explain shortcuts
make enter switch to the first match in the list
Notifications: Improve channel detection
Only update title for notifications, not other kinds of activity

Also make the unread count the first thing in the title
localstorage: Correctly check whether value is set before setting default

The old condition always overwrote boolean values that were set to false
with the default m( Check for undefined instead.
Reinitialize context when relay closes connection

Fixes #73
Use CSS classes instead of javascript for margin
Fix "Switch to buffer with activity" skipping buffers with notifications

This caused two buffer switches in a row, in effect forgetting the notifications
Fix an issue with notifications being shown when fetching old lines

@xt, does this fix the issue for you?

While we're at it, fix the annoying jump-to-bottom when loading more lines.
Fix scrolling on mobile devices

Previously, we were scrolling the div, not its contents, as it grew infinitely.
Thinner scrollbars and larger buttons on mobile

Give those buttons a size where there's at least a chance to hit them with a finger
Increase size of bufferlines on mobile

We had 10px+2% space on the bottom, that's pretty wasteful
Extend swipe region. Still not optimal.

It would be nice if we could scroll on the whole `content` div, but then the
open sidebar and close nicklist swipes collide
Adaptive nicklist width