Utilize Navigation timing api

[#1]

Integrate the Navigation Timing api into SiteCatalyst. So that the page view can also have the metrics the user experienced for how long each part of the page took to load.

This would come in handy for many correlations such as bounce rate or conversions. 

It also serves as a way for report watchers to discover which pages are candidates for improvement to pass over to their ops for site performance improvements.