Bugfix: configuration wizard crash 2 #1077
Make sure brim paths don't overlap
Revert "Smarter ordering of brim loops. #687" until new Math::Clipper is out

This reverts commit 4aad2f6243e1a3d0503a048536365492f3bc2e14.
Rename ex_int_offset2 to offset2_ex
Alwyas apply disable_fan_first_layers, even if cooling is disabled, since fan_always_on is applied in that case as well. Update descriptive text and have it appear in case of disabled auto cooling. #1166
Merge branch 'better-brim'

Conflicts:
	lib/Slic3r/Geometry/Clipper.pm
	lib/Slic3r/Print.pm
New traverse_pt()
Avoid useless looping and usage of ExPolygons
One more offset_ex() optimization
Incomplete work - still wrong order
Perimeters refactoring complete
Correctly detect external hole perimeters
Move gap fill to its own method
Code cleanup and remove arc compensation code
Bugfix: most of the File menu items didn't work with --no-plater. #1112
Fix menus for --no-plater. #1112
Move fan_always_on in the Enable options group. #1166
Only make the inwards move when we have more than one perimeter
Move Slic3r::Test::GCodeReader to Slic3r::GCode::Reader
New --spiral-vase option to continously raise Z when printing single-walled vases. #997