Minor fix in debug code
Fix handling of dirty models with overlapping facets, where some holes became filled because of wrong slice nesting
Better compatibility with Windows in Build.PL
Avoid reinstalling Math::Libm on Windows every time
Explain user that he doesn't need to worry if a failed module was optional. One more fix for Windows, also
Keep objects vertical in 3D preview
Show axes and ground
Expose an Open button in the plater
Plater rearrange experiment
New feature: ability to override specific settings for individual objects in the plater. #344
GUI fixes for Windows
Merge branch 'master' into plater2

Conflicts:
	lib/Slic3r/GUI/Plater.pm
Use multiple colors for multimaterial models in 3D preview
Show facets, materials and manifoldness in info panel
Merge branch 'master' into plater2
Distinct dialogs for 3D preview and object settings
Minor fix to font size
A couple fixes for Windows
Ability to customize how materials are mapped to extruders. #1020
Validate config before launching the object settings dialog