input.Makefile: Mapping: $(map): Removed no longer used test for $(mapEnv)

sql.py: run_query(): Exception handling: Fixed bug where PostgreSQL 9.1 PL/Python errors have a different format than PostgreSQL 9.0 which needs to be supported separately. This format was already supported in sql_gen.plpythonu_error_handler, but also needed to be supported for exceptions that propagate back to the client.

inputs/SALVIAS-CSV/src/: Removed source files because they shouldn't be under version control. (They are synchronized via `make inputs/download`.)

inputs: Moved src files into VegCSV subfolders (https://projects.nceas.ucsb.edu/nceas/projects/bien/wiki/VegCSV#CSV-representation), with table suffixes removed, using the steps at <https://projects.nceas.ucsb.edu/nceas/projects/bien/wiki/VegCSV_subfolders>

util.py: dict_subset(): Fall back to using dict when OrderedDict is not available, in order to support making the maps on nimoy

mappings/: Removed now-inaccurate ".stems" suffix from VegX-VegCore.stems.csv, which actually applied to all tables

mappings/: Removed no longer used ".specimens" suffix from maps, which is now the same for all maps

mappings/: Removed no longer used plots, organisms, and stems maps, which were copies of the specimens map

input.Makefile: Core maps: Always use the specimens "table", since there are now no longer separate mappings for different tables, and the other tables' maps in mappings/ are merely copies of the specimens table's map

input.Makefile: Removed no longer used custom via maps code, so that map files no longer need a prefix (which is always the same) specifying that they map through Veg+. Veg+ thus serves as the single gateway to VegBIEN, which avoids ever again having to maintain two copies of the mappings, as was the case when DwC and VegX XPaths were separate gateways. This will assist in untying the complex mapping logic in input.Makefile from file naming conventions in mappings/, and simplify the task of grouping each map with the CSV it maps.