Responsive table headers

Ensure that the .responsive-vertical headers do not act like the .responsive headers. If you look at:

http://dev-earthquake.cr.usgs.gov/earthquakes/eventpage/usp000qjau#scientific_tensor

If you collapse the window size down to mobile viewport size, and look at the Principal Axes table, you will see the thead > tr > th elements lose their padding and background color. 

Updated the tbody > tr > th elements to have the same text shadow as all other th headers. 

Updated the .responsive-vertical > thead > tr > th:first-child to be left aligned like all of the subsequent headers in that header column.