Fixes

Mostly GUI updates and fixes for this release

• Fixed mapping layers image unit and overlay getting confused if done in certain orders.
• Current image unit no longer available as an overlay in the pop up button.
• Chop area type popover editor table cleaned up.
• Layers inspector view tidied up.
• Fixed typo in help of mapping layers view, add extra paragraph on adding and removing layers.
• Circular warp now properly updates dimensions if image input is changed.