[SMDP] Change to C.1 Planetary Science Overview

The last paragraph of Section 3.5.2 of the Planetary Science Research Program Overview has been changed to require Proposers intending to archive data or products in the PDS to provide a letter of support from the appropriate Discipline Node indicating that the PDS is willing to accept the data submission. New text is bold and deleted text is struck through. This change applies to proposals with Step-2 due dates after August 31, 2016.