Add article repartition in stats

Add article repartition per hour, per day of week, per month for all feeds but also for individual feeds.
Add repartition statistic support in Sqlite
Small fixes to follow @marienfressinaud recommandations
Hide read feeds and read categories when in unread mode

https://github.com/marienfressinaud/FreshRSS/issues/430
There are some repeated HTML attributes (`data-unread` and `active`)
which could maybe be simplified.
If some people do not like this behaviour, we could consider having an
option.
Merge pull request #550 from plopoyop/dev

Correct bug in add/remove users
Small fixes to follow @marienfressinaud recommandations (take 2)
Remove unnecessary title property
Merge pull request #548 from aledeg/more-stats

Add article repartition in stats
Fix bug collapse and mark_read

Articles was not marked as read when open with shortcuts.collapse_entry

Fix https://github.com/marienfressinaud/FreshRSS/issues/556
Merge branch 'dev' of github.com:marienfressinaud/freshrss into dev
Basic protection against XSRF using Referer

https://github.com/marienfressinaud/FreshRSS/issues/554
Also edited the error controler to use the log message passed in
Minz_Error::error().
Changelog towards 0.7.4
Install script was not keeping all config settings

https://github.com/marienfressinaud/FreshRSS/issues/537
Strict Referer domain against XSRF

https://github.com/marienfressinaud/FreshRSS/issues/554
Dynamic favicon showing the number of unread articles

https://github.com/marienfressinaud/FreshRSS/issues/539
Works in Firefox 32 and Opera 12. Does not work in IE 11 but without
error.
We should test if icons still work in many contexts such as placing a
shortcut on the desktop of various platforms.
Dynamic favicon large numbers

https://github.com/marienfressinaud/FreshRSS/issues/539
Dynamic favicon large numbers 2

https://github.com/marienfressinaud/FreshRSS/issues/539
Dynamic favicon quick fix Chrome

https://github.com/marienfressinaud/FreshRSS/issues/539
Could be done better
Experimental: Removed lazyload.js and use postpone attribute instead

https://github.com/marienfressinaud/FreshRSS/issues/316
The performance of lazyload.js was not good enough, and not really
needed anyway.
This change mostly affects mainly situations when the content of
articles is shown by default, not so much when they are collapsed
Using HTML5 lazyload and postpone attributes by default on all img,
audio, iframe, video.
http://www.w3.org/TR/resource-priorities/#attr-postpone
Postpone attribute is removed by JavaScript if the user does not want
the lazyload behaviour.
In the case when users do want the lazyload behaviour, in normal view
with articles hidden, we furthermore use the data-original approach to
be sure to support current browsers.
+Corrected some bugs with enclosures, and some images not appearing
before the first scroll.
+Now faster regex processing img and iframe at once (was not practical
with lazyload.js)
Unicode tick without colour

https://github.com/marienfressinaud/FreshRSS/issues/560
The former was green in Firefox 32 beta