input.Makefile: Testing: Added test/import.%.staging.out test to test the staging tables. Sources: cat: Updated Usage comment to include the "inputs/<datasrc>/" prefix the user would need to add when running make.

bin/map: Fixed bug where mapping to same DB wouldn't work because by-column optimization wasn't implemented yet, by turning it off by default and allowing it to be enabled with an env var

bin/map: DB inputs: Use by-column optimization if mapping to same DB (with skeleton code for optimization's implementation)

input.Makefile: Mapping: Use the staging tables instead of any flat files if use_staged is specified

bin/map: Support custom schema name. Support input table/schema override via env vars, in case the map spreadsheet was written for a different input format.

sql.py: qual_name(): Fixed bugs where esc_name() nested func couldn't have same name as outer func, and esc_name() needed to be invoked without the module name because it's in the same module. select(): Support already-escaped table names.

main Makefile: $(psqlAsAdmin): Tell sudo to preserve env vars so PGOPTIONS is passed to psql

root map: Fill in defaults for inputs from VegBIEN, as well as outputs to it

disown_all: Updated to use main function, local vars, $self, etc. like other bash scripts run using "."

vegbien_dest: Fixed bug where it would give a usage error if run from a makefile rule, because the BASH_LINENO would be 0, by also checking if ${BASH_ARGV⁰} is ${BASH_SOURCE⁰}