Fix duplicate bubbles

After filtering, we were still displaying some points with no data.
We now remove these points when they have no data under the filter, and
add them back in later.
Applies class renaming to all points

Some of the points are repurposed for different data. In this case, the
tooltips were correct, but the dom class itself was outdated.

We now force an update of the class on all items, regardless of whether
they are new or not.
Fix missing ticks for bottom/right axis

The ticks were overlapping the axis line. Because both were 1px, the
ticks ended up being hidden.

This also flagged a case-sensitivity typo in the LightTheme.
Increase tickSize

Now that the ticks issue has been fixed, we adjust the tickSize to be
more visible.
Fix issue with points on multiple line series

The line series were only selecting all circles on the chart, then
comparing against their own data. Now, we use a classname for the line
points, which is unique for the line (assuming names are unique).

This lets us have 2 line series on a chart, and configure whether they
show or hide points independent of each other.
Update changelog
Stop NaN radius/x/y

Blocks the pointSeries from getting an undefined/NaN back from "rangeX",
"rangeY" and "rad" functions, as this causes excessive error logging
from d3.
Merge branch 'upstream' into feature/consistent-ticks
Merge branch 'upstream' into feature/two-line-points

Conflicts:
	Changelog.txt
Merge pull request #185 from tpkelly/develop

Fix axis linewidth/color drawing
Rename rangeX/Y to x/yPosition
Merge branch 'upstream' into feature/remove-duplicate-bubbles
Merge pull request #177 from tpkelly/feature/remove-duplicate-bubbles

Fix duplicate bubbles
Update Changelog
Merge pull request #179 from tpkelly/feature/consistent-ticks

Fix missing ticks for bottom/right axis
Remove spaces from CSS classname

Applies the same fix as shortClassName did, replacing spaces with "_"
Refactored Series click function:
 - Removed the unused element parameter.
 - Renamed filterFunc parameter since the expected argument is a crossfilter group object, not a function.
chartFilterHandler - rename argument to indicate that it is groupings that are filtered
Renamed ChartGroup.chartFilterHandler => filterByGrouping
Tidied ChartGroup tests