lib/sh/util.sh: added require_dot_script()

bugfix: lib/sh/util.sh: $top_script: use @BASH_SOURCE instead of $0, because this is also defined for .-scripts

bugfix: bin/import_all: restore the working dir when main() is done, in case it started as something other than the root dir

bin/after_import: support turning off the end-of-import backup for imports that are not the full database

bugfix: lib/runscripts/util.run: `trap on_exit EXIT`: only set this if the script is not a dot script, because if it is a dot script, on_exit() will not be invoked until the calling shell exits, which may be much later than when the script is run. previously, this was handled by canceling the EXIT trap if on_exit() is run manually, but this would not work correctly if a load-time error prevented on_exit() from running and canceling the trap.

bugfix: lib/runscripts/util.run: if is_dot_script, fix $ when no args causes this to incorrectly contain the script name. use is_dot_script rather than the presence of $ args to decide whether to use @BASH_ARGV, because @BASH_ARGV is actually wrong when run as a .-script (it contains the script name).

bugfix: lib/sh/util.sh: is_dot_script(): need to subtract 1 from ${#BASH_LINENO[@]}, because this is the array length rather than the index of the last element as in Perl

lib/sh/util.sh: added is_dot_script()

bugfix: schemas/vegbien.sql: taxondetermination_set_iscurrent(): is_datasource_current (used by analytical_stem_view): need to separately check if `determinationtype IS NULL`, because `determinationtype NOT IN (accepted, matched))` will return NULL (false) if determinationtype is NULL, causing no match

bugfix: bin/make_analytical_db: when running into a public schema other than "public", also pass this to `/run export_` (which currently uses $schema instead of $public)