Deal with ambiguous config key for `tailbone.url`

now must use `tailbone.url.base` instead

Allow suppress warnings for ambiguous config key

needed for temporary fallback checks

Add "ignored" status code for pending products

some products just will never make the cut

Add product/image URLs for product autocomplete results

also add (optional) "key" search for products autocomplete

Add the `RattailConfigMixin` class

to keep common methods in one place, while we refactor all this...

Always add "change due" line when finalizing POS batch

also set extra attrs on batch when assigning customer

Add `AppHandler.make_counter()` method

for when you just need a "dynamic" sequence

Add first attempt for food stamps tender at POS

definitely this is not working right yet..will have to circle back to it

this also filters out "not for sale" products in lookup/search methods

Add current (e.g. sale) price for POS batch row

also `txn_price_adusted` flag

Add basic support for suspend/resume of POS txn batch

so far, assumes there is only one DB in the mix. but needs to also
handle the (presumably more common) case of storing suspended
transactions on a central server DB

Add basic support for open rings in POS batch

added `Department.tax` and `.food_stampable` to that end

Assume default paths for `config.appdir()` and export files dir

no need to require config for those paths, they have yet to vary

Improve tax support for POS batches

also add ref to tender, in batch rows

Add `override_price()` method for POS batch handler

probably a bit simplistic, may need to better track before/after
prices within the main row?

Add enum for `POS_ROW_TYPE`

to be continued i'm sure

Reset tender, void when cloning POS batch

the point of cloning is to re-test finalizing, so make sure it is not
already finalized

Add email template/config for uncaught exception

for use with POS GUI

Grow diff percent column for pricing batch

sometimes cost values may be way off, and result in wild diffs

Add simplistic "change back" if tender overpays for POS batch

still need a way to (better) notify caller of what happened? or maybe
the rows are enough

Add tenders, more columns for POS batch/rows

just basic tenders so far, probably need to expand that later

Cannot assume that Session exists when making config

sqlalchemy is not always installed

Fix broken test

now that we *do* provide a default for app_title

Change how we get the app/node title

app handler must be responsible for these (and probably more..)

Add new customer to session when first making it

i guess previously i thought make_customer() should not *necessarily*
add it to session, but in practice it can cause issues if we don't.
hopefully now there aren't yet more issues b/c we do..

Fix default behavior of start/end dates for importers

if command etc. does not specify start/end date, then we really can't
default to e.g. "today" b/c that would typically filter out most of
the data. if a given importer needs to do such a thing, it should do
so explicitly

so an importer should always have `start_date` and `end_date` attrs
set but they may be None (same for start/end time)

Add initial model, handler for POS batch

lots more to come yet, savepoint

Try using backslash to escape newlines in SIL strings

thanks https://stackoverflow.com/a/54336425

Do not cache empty data when normalizing local for importer

i.e. normalize_local_object() should be allowed to return None in
order to omit some object(s) from cache

Add setting to auto-make credits for "presumed missing" items in receiving

previously we always created these credits, now we do not by default

Bypass temp file for postgres backups; dump straight to gzip

hopefully cut down on disk usage when doing the dump