* Improve the way we do queries
* PHP legacy compatible
* Update aproach to filter queries with empty values
* Fixing Unit Tests
* Moving Unit Test to its the correct test function
* Filter missing the new param, allow_empty, also simplifiying unit test.
* Helper function to create counpon does not support empty coupon codes
* Helper function does not need to allot empty search
* Wrong code standard
* Fixing Code Standard Unit Test
* Fixed case for all _e, esc_attr_e and esc_html_e strings
* Fixed case for all _n_noop strings
* Fixed case for all _x strings
* Fixed case for all __, esc_html__ and esc_attr__ strings
* Fixed a few more strings
* Fixed strings in unit tests
* Fix PayPal Standard case.
* Save Order text