Merge branch 'master' into 'master'
In a flexform (f.e. powermail) the RTE id can have a . which has to be escaped t… …o make the jquery selector work. The RTE's id in the powermail flexform tab "Submit Page" is RTEareadata_tt_content__213002__pi_flexform__data__thx__lDEF__settings.flexform.thx.body__vDEF_. But the . breaks the jQuery selector, so we have to escape it. See merge request !8