Left and Right margin values appear (randomly?)
When inserting new widgets, Left and Right margins appear (as yet, I haven't detected a pattern):
- These then cause deprecation warnings
- Possibly these values are copied at some point from the Start/End margins?
- They Left/Right values seem to appear always when copy/pasting widgets
- Margins (in general) are frequently shown incorrectly in Glade, but do appear in the final project. In some cases, the widgets are even shown (in Glade) with a negative margin (ie. outside the container)