bugfix: schemas/vegbien.sql: schemas/vegbien.sql(): need to util.use_schema(schema_anchor) before initializing vars that use own-schema functions

*{.sh,run}: runscript targets: use begin_target instead of echo_func so the target name is properly echoed. note that this requires using with_rm so that $rm is properly progagated to applicable invoked targets. (previously, $rm was progagated to all invoked targets. note that with_rm only works inside a runscript target that starts with begin_target.)

schemas/vegbien.sql: updated _specimens_01_count_of_total_records_specimens_in_source_db

schemas/vegbien.ERD.mwb: regenerated exports

schemas/vegbien.sql: public_validations: added _specimens_01_count_of_total_records_specimens_in_source_db

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)

fix: schemas/VegCore/mk_derived: added `EOF` at end to avoid (benign) "here-document delimited by end-of-file" warnings on Linux

fix: schemas/util.sql: trim(): by default, cascadingly drop dependent columns so that they don't prevent trim() from succeeding. note that this requires the dependent columns to then be manually re-created.

added schemas/VegCore.ERD.pdf symlink for easy access

bugfix: schemas/util.sql: is_constant(util.col_ref): updated to include standard newline at beginning of comment (applies to newly-imported staging tables)