Svg improvements, also more verbose images-test page

[jensens]

need merged and tested with/after merge of plone/plone.scale#68

[mister-roboto]

@jensens thanks for creating this Pull Request and helping to improve Plone!

TL;DR: Finish pushing changes, pass all other checks, then paste a comment:

@jenkins-plone-org please run jobs

To ensure that these changes do not break other parts of Plone, the Plone test suite matrix needs to pass, but it takes 30-60 min. Other CI checks are usually much faster and the Plone Jenkins resources are limited, so when done pushing changes and all other checks pass either start all Jenkins PR jobs yourself, or simply add the comment above in this PR to start all the jobs automatically.

Happy hacking!

[jensens]

@jenkins-plone-org please run jobs

[mauritsvanrees]

I have released plone.scale 4.2.0 which has the method that you added there. I have updated 6.0/1/2-dev on dist.plone.org.

Meanwhile Jenkins tests fail with:

Unicode strings with encoding declaration are not supported. Please use bytes input or XML fragments without declaration.

[jensens]

@jenkins-plone-org please run jobs

[jensens]

@mauritsvanrees all green now