Implement c3ext.js with new zoom and auto dataset reduction feature
move mouse wheel zoom from sample file to c3ext.js code
Cleanups
Rename onend to done in flow API - #314
Merge branch 'feature/autoreduce' of https://github.com/danelkhen/c3 into danelkhen-feature/autoreduce
Fix trivials of sample for reduction by zoom - #310
Merge branch 'danelkhen-feature/autoreduce'
Rename onenter/onleave to onmouseover/onmouseout
Update sample for padding
Fix tick width when no tick exists - #295
Show gauge label when value is 0