For now, just mesh import. Supports all geometry nodes in Rendering, Geometry3D, CAD geometry modules. No support for materials, color, or textures. Normals in the file (if any) are ignored. Light sources, viewpoints, sensors, world, shaders, scripts also ignored.
This way the user can add a setting that is not made visible in the sidebar. Adding a specific setting no longer needs a detour through the setting visibility preference page.
CURA-1799
As discussed on GitHub we don't need a complete traceback on HTTPError.
However URLError should return a full traceback, like any other
exception that might occur.
The value property was sometimes not set. In the default case, this just added an empty setting instance (for a particular key), which appeared to do nothing until you've changed it. This appears correct because if it's not changed then it should be the same as the extruder's value, but if you then change the extruder's value it doesn't update its visible value but still has no value in the setting instance, so the value still falls back to the extruder and the setting ends up different from what is being displayed.
Contributes to issue CURA-1988.
Setting .value creates a new Python attribute in the object. Setting with setProperty creates the setting property, like we wanted.
Contributes to issue CURA-2011.
Due to a gnawing feeling in the back of my head, I tested this with an UM2 and adding settings failed there. This fixes it.
Contributes to issue CURA-2011.
Upon adding the setting (making it visible) it takes the setting from the support extruder stack. It doesn't update afterwards.
Contributes to issue CURA-2011.
So far I ran 2 or 3 times into the problem that my engine was not up to
date. The bad thing here is that there is always an updated version from
my PPA on the PC. So first this commit gives the possibility to look for
CuraEngine in the $PATH directories. Before I had to copy it always
manually, eg. via "cp $(which CuraEngine) bin/CuraEngine" in my
workbench.
Second, people can get into the situation that CuraEngine is missing at
all. So before making Cura loop and try to use an executable that does
not exist, better raise an Exception here.
An additional info message tells about the location being used.
Does not contribute to any JIRA issue (I think), but makes my life
easier.
