schemas/vegbien.sql: implemented _plots_08_list_of_plots_which_use_percent_cover

validation/aggregating/plots/bien3_validations_salvias_vegbien.sql: updated to DB

schemas/vegbien.sql: implemented _plots_07_list_of_plots_which_use_counts_of_indiv_per_species

validation/aggregating/plots/bien3_validations_salvias_vegbien.sql: updated to DB

bugfix: inputs/SALVIAS/validations.sql: plots_07_list_of_plots_with_counts_of_individuals_per_species: renamed to _plots_07_list_of_plots*which_use*_... because this query is not intended to include the actual counts, just to say which plots have them (the correct "which use" wording is also used in queries #8, 9)

web/links/index.htm: updated to Firefox bookmarks: PostgreSQL: query planner: documented how to prevent incorrect query plans (`SET enable_seqscan = off;`, etc.)

web/links/index.htm: updated to Firefox bookmarks: PostgreSQL: query planner: documented that incorrect query plans are an ongoing bug in Postgres, because it does not support index hints and by default does not follow the join order. specifically, Postgres often does the following things in query plans which should normally never be done:...

schemas/vegbien.sql, inputs/SALVIAS/validations.sql: added _plots_06a_list_of_stems, for use in figuring out the diff in _plots_06_list_of_plots_with_stem_measurements

validation/aggregating/plots/bien3_validations_salvias_vegbien.sql: updated to DB

schemas/vegbien.sql: plot: removed explicit column lists added in the autorename of plot.location_id->plot_id