simple hack to get elastic to work with binned groups

i don't claim this is correct or general, just want to keep the conversation
moving

Conflicts:
	dc.min.js
build docs from source
Fix #270
Merge pull request #301 from NickQiZhu/build-docs

Build docs from source
fix sourcemap - use for min only
remove vestigial getDataWithinXDomain
add .defined and .colorAccessor to line chart
run grunt default only once for web task
clean up some coloring issues and add a colorDomain function
more example
some initial work to add missing docs
start to redo tutorial as docco
add number display to api TOC
add tests for number display. Closes #291
Prepare for 1.6
  remove scatter
  update versions Fixes #278
bump to 1.7.0-dev
more authors
refactor to call .data() rather than group().all()
deregisterAllCharts with an optional group (like filterAll and renderAll)
build artifacts for #315
do not filter for brush events with zero brush length