Allow Integrator to define rules to track views of records.
This allows to add tracking to extensions like tx_news.
Integrators are able to define matching rules on current request. If a
request matches, the record is stored as individual view beside existing
pageview.
Relates: #14
Extract operating system from user agent and store it in database
record.
Another widget is added which displays the page views per operating
system.
An command is provided which will update existing data.