Make minimum planner speed configurable
pop all flushable blocks for queue in one on_idle
Add M205 Sxxx to set minimum planner speed from console and save with M500
Merge pull request #311 from wolfmanjm/upstreamedge

Make minimum planner speed configurable
Replace tabs with spaces
Merge branch 'edge' of git://github.com/arthurwolf/Smoothie into edge