WooCommerce Lightspeed POS Integration 2.16.0

* Fix - Fixes a major bug where WooCommerce products that have sync enabled were not pulling LightSpeed inventory before checkout

* New - New feature "Delete Lightspeed categories cache" - remove any LS categories in the cache. Forces the plugin to stop trying to link products' categories with ones that were imported.
* New - New "wclsi_sync_prod_inventory" filter that filters the $wc_prod object before syncing its inventory to Lightspeed
* Fix - Fixes a bug that was introduced in 1.6.8 that does not re-load the "wclsi_poll" action scheduler job
* Tweak - Enhances error and notification experience

* Fix - Fixes a bug where stores with duplicate SKU products were not being updated via auto-sync or manual sync
* Fix - Fixes a bug where 'wclsi_poll' and 'check_for_new_ls_prods' action scheduler jobs show up more than once under the 'pending' section
* Fix - Fixes a bug where imported products with categories are automatically added to 'Uncategorized' (or whatever the default category is)
* Fix - Fixed a bug where imported products (but not on the sync schedule) were still being updated on Lightspeed after a WooCommerce update
* Tweak - Re-arranges selective sync checkbox to display legacy Web Store fields
* Tweak - Removes CSS around hiding selective sync fields