Remove the ng-binding class from text before lookup

When using ng-href and related directives, the 'ng-binding' class gets added to elements before the translate directive can get to it. This patch strips the ng-binding class from elements inside the translate directive to that the msgid lookup succeeds.
Corrected this in 8fa33ba. I'm cool with having Afrikaans in the test suite [1], but it needs to be in the right language code.

[1] I have very fond memories of South Africa.