Safari: use product version numbers instead of those in the user agent string #1123

currently piwik is showing the webkit number for safari and not the versionnumber of Safari.

For most webmasters it would be better to see which version (Safari 4, 3 and so on) is used by his visitors.

http://en.wikipedia.org/wiki/Safari_version_history

Requires changes to libs/UserAgentParser.

There's also been requests to split out Webkit browsers into a separate browser family (Webkit), identify the IE layout engine as 'Trident', and similarly, 'Presto' for Opera browsers.

(In [1815]) fixes #1123, fixes #1132 - convert WebKit version numbers to Safari product versions; add Epiphany browser detection; re-organize browser families for consistency