Check existence of nonce Closes #5050
Set default for $plain_text variable. Closes #5051
Fix variation price display by checking if a variation is actually stock managed before comparing to stock amount Closes #5059
When dealing with fixed_product discounts, when doing it for the line, multiple by product qty Closes #5054
We can hide suffix for prices in admin lists Closes #5048
Fix bulk edit % increase and decrease Closes #5068
pedantic nonce checking
When getting downloadable files, check access_expires too Closes #5060
Fallback for add ons page loading
get_related fixed tags OR query not excluding product ID
Changelog bump for 2.1.5 changes