API change of UILayout.template_list, fixed.
Merge branch 'master' into prerelease (used amend in master branch)
Merge branch 'master' into prerelease
UI: 3D toolbox: tabbed interface, split panel into two
rename 'Make Unfoldable' -> 'Unfold' everywhere
new operator: Clear All Seams
replace license block with a nicer one
API update: 2d cross product. Removed the cross_product function
Merge branch 'master' into prerelease

Conflicts:
	io_export_paper_model.py
use `tempfile` module for embedding images, instead of random names
style changes (a *lot* of them)
three critical fixes