intervals: better interval splitting in case the range is not big enough
intervals: better interval splitting in case the range is not big enough

If more splits are requested than possible, the smallest key range is used, e.g.
> intervals:split(intervals:new('[', 0, 3, ']'), 10)
results in
> [[{interval,'[',0,1,')'}],
   [{interval,'[',1,2,')'}],
   [{interval,'[',2,3,']'}]]

-> not perfect but better than returning [[{interval,'[',0,3,']'}]] as before!
caijieming-baidu/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,jvf/scalaris,caijieming-baidu/scalaris,jvf/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,jvf/scalaris,scalaris-team/scalaris,jvf/scalaris,caijieming-baidu/scalaris,jvf/scalaris,caijieming-baidu/scalaris,jvf/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,jvf/scalaris,scalaris-team/scalaris