* DEV: unsilence deprecation warnings for old Font Awesome icon names
* update fa-user to user font awesome icon name
* update pencil-alt to pencil font awesome 6 icon name
Our 'page_view_crawler' / 'page_view_anon' metrics are based purely on the User Agent sent by clients. This means that 'badly behaved' bots which are imitating real user agents are counted towards 'anon' page views.
This commit introduces a new method of tracking visitors. When an initial HTML request is made, we assume it is a 'non-browser' request (i.e. a bot). Then, once the JS application has booted, we notify the server to count it as a 'browser' request. This reliance on a JavaScript-capable browser matches up more closely to dedicated analytics systems like Google Analytics.
Existing data collection and graphs are unchanged. Data collected via the new technique is available in a new 'experimental' report.
The title had to be added both on the 404 page generated by the server
side, displayed when the user reaches a bad page directly and the 404
page rendered by Ember when a user reaches a missing topic while
navigating the forum.
If the setting is turned on, then the user will receive information
about the subject: if it was deleted or requires some special access to
a group (only if the group is public). Otherwise, the user will receive
a generic #404 error message. For now, this change affects only the
topics and categories controller.
This commit also tries to refactor some of the code related to error
handling. To make error pages more consistent (design-wise), the actual
error page will be rendered server-side.
