1.2: Support gtag (#8)

* add the js code for the gtag compatible event

* add the settings needed to choose between old Analytics and new Gtag

* update .pot file

* Fix typo

* updated translation

* Update Readme, changelog

* ver 1.2

1.1.4

var 1.1.4

1.1.3

ver 1.1.3

1.1.2

ver 1.1.2 - Set minimum PHP requirement to 7.0

1.1.1

ver 1.1.1 - Fixed Italian Translation

1.1

ver 1.1 - Implemented a settings page in WP Dashboard. Close issue #2

1.0.1

Fix sending the event onOfflineSubmit

1.0

ver 1.0