bugfix: lib/runscripts/*: calls to rm: use `rm -f` instead to avoid an error (which aborts the program) if the file does not yet exist

inputs/VegBank/: added taxon_observation.** left-join of the tables, using the steps at http://wiki.vegpath.org/Left-joining_a_datasource

inputs/VegBank/taxonobservation_/create.sql: join starting with taxoninterpretation so that we can use the taxoninterpretation_id as the row_num (text strings, formed from concatenated #s cannot be used as a row_num). there is only 1 taxonobservation without a taxoninterpretation, so we can just include one row for each taxoninterpretation.

bugfix: inputs/VegBank/taxonobservation_/test.xml.ref: updated after reloading staging table. this fixed a bug where observationGranularity apparently either did not exist or was not the right type of constant column to be properly inlined the last time the tester was run. the inlining is important for using metadata switches to generate the correct XML import script.

bugfix: lib/sh/make.sh: don't allow rm to override remake if an invoked script uses this file. this fixes a bug in `rm=1 inputs/.../.../run` where the remake action would be invoked on the map_table command even though it had been suppressed, because it was run externally (i.e. make.sh was reloaded) and the rm=1 flag was still active

schemas/VegCore/ERD/VegCore.ERD.png.map.htm: reordered in dependency order: moved traceable before party because party is a subclass of it

bugfix: inputs/input.Makefile: `%/install: %/create.sql`: don't include %/header.csv as a target, so that it won't get deleted if the install fails (especially on a step that happens after the header is exported)

inputs/VegBank/taxonobservation_/postprocess.sql: added primary key. note that the inserted row count changes, most likely because the rows are now in sorted order.

inputs/VegBank/stemcount_/postprocess.sql: added primary key. note that the inserted row count changes, most likely because the rows are now in sorted order.

bugfix: schemas/util.sql: mk_subset_by_row_num_func(): need explicit ORDER BY on the row_num_col, to prevent PostgreSQL from sorting the rows in reverse (they will be sorted because of the index scan, but the direction is otherwise indeterminate)