Allow inline SVG support

[Kristina Hoeppner]

In bug #1681571 the support for uploading of SVG is going to be implemented. This is a follow-on wishlist item to also allow inline SVG so the SVG properties can be changed directly in Mahara.

This can take a couple of different forms:

1. In a text box (anywhere there is TinyMCE): Tick a box / flip a switch to activate inline SVG and then see the SVG properties in the pop-up so people don't have to go to the text box source.

2. If we also allow the manipulation in an image block add the SVG properties there once inline SVG is activated.

I would think that the SVG properties manipulation should probably not happen in the file browser itself as you could upload a black SVG and then use it as a white one in one page and a red one in another. If we allow for the changing of the SVG properties in the file browser, we could only save one version rather than use both.

In reveal.js (at least via slides.com) I can activate the inline SVG version for images directly on a slide and then go into the source to make changes, but I'm not saving those changes with the file itself, but just in the slide properties so I'm more flexible with the file in other contexts.

[Kristina Hoeppner (kris-hoeppner)]

This is an extension of bug #1681571, allowing the upload of SVG.