- update the common problems page with the section about data not loading because of python...changed the solution instructions now that we bundle python with cave
- update the d2d-perspective page so it has a subsection on how to remove an individual resource using the resource menu
- add an image for single resource unloading
- removed all images that don't apply for v20
- removed several extra files that aren't necessary (in the docs/pdf/ and docs/python/ directories)
- renamed some images that were preserved that had random character names, to something descriptive