Add RA summary pages, fixes #26
Add dropdown to nav for RA views
Add NERACOOS logo
Updates the view for the asset map

 - Adds rowspan to mach the number of rows in the variable
   names/variable units
 - Passes in another dict key "varcount" to view to assist in rendering.
Updates the metadata model to pair name and units

 - Wicken doesn't maintain the order between the names and units so this
   is a patch that deliberately fills in explicit metadata.
Adds more comments and descriptives
Fixes stack trace logging
Merge pull request #89 from ioos/units

Fixes the metadata relationship between the variable names and the units
Merge branch 'ra_pages' of https://github.com/ioos/catalog into ra_pages
Added regional/national provider distinctions
Added regional/national providers to index page dropdown
Minor metadata cleanup for providers
Merge pull request #59 from ioos/ra_pages

RA Summary Pages
Set max-height on image files, fixes #26