add color4f to docs

Add SkPaint::setColor4f and getColor4f. Another pass will
be required later once fiddle updates itself.

Also add checks to bookmaker so it doesn't write status
if generated files are unchanged; and deletes temporary
files in working directory.

R=brianosman@google.com

Docs-Preview: https://skia.org/?cl=151365
Bug: skia:6898
Change-Id: I8059641f19017a86fc4b63ebd9ff784716365967
Reviewed-on: https://skia-review.googlesource.com/151365
Commit-Queue: Cary Clark <caryclark@skia.org>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: Cary Clark <caryclark@skia.org>
Reviewed-by: Brian Osman <brianosman@google.com>
5 files changed