WooCommerce Lightspeed POS Integration 2.16.6

* New - Removes the need to have allow_url_fopen = on, moves image downloads to native wp_remote_get() function
* Fix - Fixes some issues around Javascript setTimeout() functions that were introduced in v1.6.2. Should help reduce 429 errors.

* New - Adds a "Stock Quantity (non-manual updates, e.g. orders)" selective sync setting specific to WooCommerce Orders, if checked it will sync inventory to Lightspeed after a WooCommerce order is completed
* Fix - Fixes a sync bug where image changes in Lightspeed were not being synced over to WooCommerce
* Fix - Fixes a sync bug that could have locked the poller from syncing for long periods of time (possibly hours)
* Fix - Fixes a sync bug where inventory was inadvertently being synced over to Lightspeed

* Fix - Fixes a bug that was introduced in v1.5.9 where new LS products were not being automatically loaded
* Fix - Fixes a bug where attributes for variable/matrix products were not being synced over to WooCommerce correctly
* Tweak - Changes the syncing algorithm to look back an extra 30 seconds allow some overlap in updates made in LS