Detect crashed mysql tables & display a message in the UI #2194

When the log tables are crashed, the SQL error /exception is caught upstream, and it is not displayed in the UI. The report shows "No data" but not the error.

However in the API, the error is displayed:

su www-data -c "sh /home/piwik/misc/cron/archive.sh"
Starting Piwik reports archiving...

Archiving period = day for idsite = 1...
<?xml version="1.0" encoding="utf-8" ?>
<result>
        <error message="SQLSTATE[HY000]: General error: 145 Table './piwik_demo/piwik_log_visit' is marked as crashed and should be repaired" /       >
</result>
Archiving period = week for idsite = 1...

We should detect such error in the UI, and display a warning message in red / yellow, telling the user that statistics are not tracked because tables are crashed.

Definitely important to show these errors in the UI at all times.

Actually, current behaviour is fine

• Archiving script, if a table is crashed, will report the error
• UI: the Visitors > Overview will show the error