closes PR 12349, closes PR 10396
The macro stepper tool broke when DrRacket started doing expansion
earlier, before eval handler gets control. This commit changes the
macro stepper to just expand module contents. No REPL, no evaluation.
The long-term fix might be to make the macro stepper cooperate more
closely with the module language.
- SVG icon sources
- Playback-style icons, logos, stop signs, magnifying glasses, etc., in diffuse and shiny styles
- Program to pre-render SVG files (icons/private/svg/render-png.rkt)
- Pre-rendered icons (PNGs in power-of-2 sizes)
- Made `icons' a module, with functions to conveniently load icons and convert to/from picts
- Scribble docs for `icons'
- Used new icons in DrRacket toolbar
