move colormaps from layers folder to resources folder

[sofroniewn]

Description

Resolves #152.

Type of change

• Bug-fix (non-breaking change which fixes an issue)

References

How has this been tested?

• run examples scripts

Final checklist:

• My PR is the minimum possible work for the desired functionality

[kne42]

LGTM! Don't forget to change MANIFEST.in. While you're at it, please also rename all instances of napari_gui to napari in there :)

[royerloic]

Ressource folders are almost always reserved for non-code files such as icons, images, text files, etc...
I see a lot of python code going into the ressource folder, which i am not sure makes sense.
I am perfectly happy with colormaps living in a napari.colormaps package.

What would make sense to move to ressources is any text file (non .py) that would describe colormaps, if there is such a thing...

[sofroniewn]

Ok, that sounds reasonable - does @jni want to weigh in before I move anything again?

[jni]

He does not. =P But he agrees with @royerloic's general gist. =)

[sofroniewn]

@royerloic how about a colormaps folder inside the util folder?

[sofroniewn]

Have now moved to util folder. If @royerloic approves and tests pass he can merge

[royerloic]

You are going to hate me...
I would simply have the colormaps in:
napari.colormaps

util packages usually contain utility methods and classes used internally multiple times.
If we forsee people adding colormaps by invoking classes or methods from this colormaps
package, I would really expose it as 'napari.colormaps'.

It is not a big deal at this point, we can revisit that later.

[kne42]

IMO seeing as how these colormaps are specific to image layers, they should live in th3 _image_layer folder. Users who want to add more should add a new entry to Image.colormaps.

[jni]

Totally possible to colormap points, lines, shapes... =)

[jni]

(even desirable)

[sofroniewn]

These are all good points, we also need to curate the list of colors available for the marker edge_color and face_color which right now is a giant list. We might want to that inside a napari.colors or napari.colormaps too.

I will leave this PR for now, but we can revisit when we address some of our other color related issues like #97

We might also want to look at the organisation of util again too, including the misc.py which is a bit of a grab bag right now.