Add a header with login and registration links

This makes it easier to test and demo auth and registration.
Clear previous eco results on search

Because a large eco search takes seconds clearing the previous search
is a cue that something is happening. In the future, this will most
likely be replaced by some sort of spinner.
Fix eco template to reflect updated view response

The names of the keys in the basis dictionary changed at some point,
making the template always show empty values for plot and tree counts.
Merge pull request #115 from jwalgran/topic/auth-header

Add a header with login and registration links
Merge pull request #118 from jwalgran/fix/eco-results

Fix eco results