inputs/SALVIAS/validations.sql: use plot_code instead of plotcode for easier readability

fix: schemas/vegbien.sql: rm_all_queries(): all-schemas mode: also remove queries that are only present on the input side, so that the input side can also be re-created from the DDL file

fix: schemas/vegbien.sql: rm_all_queries(): documented that this actually does remove queries in all schemas when schema is NULL, because rm_query_view(public_validations.view) searches all schemas

schemas/vegbien.sql: top_plot view: renamed to plot, as requested by Brad (wiki.vegpath.org/2014-02-27_conference_call#schema-changes)

schemas/vegbien.sql: location.top_plot: renamed to plot_location_id, as requested by Brad (wiki.vegpath.org/2014-02-27_conference_call#schema-changes)

schemas/vegbien.sql: location.top_plot: renamed to plot_location_id, as requested by Brad (wiki.vegpath.org/2014-02-27_conference_call#schema-changes)

schemas/vegbien.sql: source_by_shortname(): documented exact time that the slow query ran for (5013s = ~1.5 hours)

schemas/vegbien.sql: public_validations: schema comment: documented how to sync the queries with schemas/vegbien.sql

schemas/vegbien.sql: public_validations.rm_all_queries(): when called with no args, operate on public_validations instead of all schemas, since this is the more common use case (replacing just the output queries, not both input and output)

schemas/vegbien.sql: rm_query_group(): documented that this only removes validations output queries (in public_validations), as it is designed for use in updating all output queries at once from the testing DB