add NON_MATCHING_ALPHA attribute to overlay

changed milestone to %v19.0.0~alpha.0

changed title from add NON_MATCHING_ATTRIBUTE to overlay to add NON_MATCHING_ALPHA attribute to overlay

created branch 2263-add-non_matching_attribute-to-overlay to address this issue

mentioned in merge request !1886 (merged)

it can be done using header option (value 0-255):

#NON_MATCHING_ALPHA=100

added in progress label

mentioned in commit 0e2564dc

closed with merge request !1886 (merged)

reopened

mentioned in merge request !1890 (merged)

mentioned in commit 4d6b50df

closed with merge request !1890 (merged)