update pie chart radius documentation (its default is auto not 90px)
Merge branch 'master' of https://github.com/dc-js/dc.js
get latest and cure bitrot in box-plot-spec

still running into axis trouble with row-chart-spec
fix rowChart rootValue()

there was already a pretty hacky check for -Infinity
but then d3.scale.log changed (from d3.interpolateNumber)
to return NaN instead, so check for that as well

this is all in lieu of real log scale / root / non-zero-start support