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
Update CONTRIBUTING.md
build examples index on web server
annoying formatting changes

probably caused by npm update
fix broken link

fixes #747
add 1.7.0 api doc
ignore unused parameters (but not variables)

it's often necessary to declare parameters that aren't used
it would be dumb to make the code less legible to please jshint
add titles for filter handler functions, and clarify a bit

fixes #737
allow clearing of a single renderlet or all renderlets
merge in clear-renderlets