JS tracker should support CSS class matomo_ignore as alias of piwik_ignore #16193

From email feedback:

Hi, I'm noticing some strange issues with matomo.js. For example. the js tracking guide indicates that using the class 'matomo_ignore' should result in the matomo ignoring link downloads, however, i am finding that does't work, while the class 'piwik_ignore' does cause the element to be ignored. Is the documentation wrong? or is it possible that the cdn is serving an older version of the tracking code?

Our guide mentions matomo_ignore here: https://developer.matomo.org/guides/tracking-javascript-guide

@mattab you are linking to the docs for 4.X which have been updated for the upcoming beta.

It's not mentioned in https://developer.matomo.org/3.x/guides/tracking-javascript-guide

This particular one we can backport though as an exception