root Makefile: VegBIEN DB: Schemas: Added schemas/%.sql to extract a compressed custom-format backup to plain SQL

root Makefile: VegBIEN DB: Schemas: Added schemas/%.backup/uninstall so that a schema can be removed by its backup file name (with extension) as well as its name

README.TXT: Documented that files and directories can easily be remade with `make <file>-remake` and `make <dir>/remake`, which do the make clean or rm automatically

pg_dump_vegbien: Added plain env var which creates plain text output instead, for use in debugging and validation

input.Makefile: Mapping: $(map): Fixed bug where use_staged was causing in_schema, in_database, etc. to be set even when not outputting to vegbien, causing bin/map to try to output to a DB when it should output to stdout, by moving the use_staged test to $(map2db)

sql_io.py: put_table(): Creating full_in_table: If out_table is a SQL function, just use in_table because in_table is not modified

input.Makefile: Documentation: import/steps.by_col.sql: $(steps): Fixed bug where stderr needed to be redirected to stdout so that it would be passed to debug2redmine and included in the file

root Makefile: Datasources: import: Don't pause after "To import all inputs at once" message because this prevents running sequential import with & (as `make import &`)

sql.py: create_table(): Only version temp tables, so that e.g. staging tables are not created with a version # if they already exist. This will help make `make install` idempotent.

input.Makefile: Import to VegBIEN: $(import): Only redirect stderr to stdout if outputting to a log file. This allows unlogged imports to redirect the "Inserted # new rows into database" message, which is output to stdout rather than stderr for use by validation and automated testing, to a separate location.