bugfix: mappings/VegCore-VegBIEN.csv: prefixed taxonomic ranks: use _concat_nullify() so that the prefix is only added if the epithet is non-NULL

fix: mappings/VegCore-VegBIEN.csv: mapped DwC year/month/day, which are split-date alternatives to eventDate. this fixes the missing eventDate in FIA.

mappings/VegCore-VegBIEN.csv: mapped subspecies to new taxonverbatim.subspecies for easier access by validations queries

fix: mappings/VegCore-VegBIEN.csv: taxonoccurrence.sourceaccessioncode: need to populate from aggregateOrganismObservationID when only that is available

schemas/vegbien.sql: specimenreplicate.institution_id: renamed to duplicate_institutions_sourcelist_id, as decided in the conference calls (wiki.vegpath.org/2014-03-13_conference_call#schema-changes-2)

mappings/VegCore.htm: regenerated from wiki: rename specimenHolderInstitutions to specimen_duplicate_institutions, as decided in the 2014-03-13 conference call (wiki.vegpath.org/2014-03-13_conference_call#schema-changes-2). note that most schema changes (such as this one) involve mappings changes, which are handled automatically by `inputs/run postprocess; yes|make inputs/{NVS,SALVIAS,TEAM}/test`.

inputs/input.Makefile: verify/%.out: use a *.sql file in the verify/ directory itself to generate *.out, so that each datasource can have its own set of output queries. for datasources that should share the same set of queries, they can instead be symlinked to the same file.

mappings/VegCore-VegBIEN.csv: event__participant: allow multiple event__participant columns

mappings/VegCore-VegBIEN.csv: project_participant: use [!...] negative lookahead assertion so that multiple project_participant columns will properly map to separate projectcontributor rows

moved everything into /trunk/ to create the standard svn layout, for use with tools that require this (eg. git-svn). IMPORTANT: do NOT do an `svn up`. instead, re-use your working copy's existing files with `svn switch` (http://svnbook.red-bean.com/en/1.6/svn.ref.svn.c.switch.html).