schemas/public_.sql: _km_to_m(): made it a wrapper around util._km_to_m() so this function is only in one place
schemas/Makefile: vegbien.sql: also include geoscrub, TNRS schemas, as requested in the 2014-04-10 conference call (wiki.vegpath.org/2014-04-10_conference_call#VegBIEN-schema). this involves having a separate public_.sql file for restoring the public schema.