Fixed failing legend tests in SpecRunner

Tested in Chrome, Firefox, IE11, Opera, Safari
Added spy to fix failing theme test in some browsers including Firefox.

Tested in Chrome, Firefox, IE11, Opera, Safari
Merge pull request #143 from niksoper/theme-tests

Added spy to fix failing theme test in some browsers including Firefox
Merge pull request #142 from niksoper/legend-tests

Fixed failing legend tests in SpecRunner
Initial clean up of axis and chart test
Update axis bound calculation and associated test
Update testing around insight.Utils.getElementStyles
Implement part of axis label dimension calculation
Removed unnecessary .calls and .applys from Axis.initializeScale.
Removed the separate findMax function definition from each series.

All series now use the base Series findMax function.
Added Chart.seriesIndexByType for supporting positioning of multiple row or column series in one chart.
Minor renaming: groupedbarThickness => groupedBarThickness
Fixed error declaring private variable.
Tests for findMax on each series
Implement more functionality for `calculateLabelDimensions`
Multiple RowSeries or ColumnSeries on one chart.
Fixed problems with axis ordering.
Updated comment for Chart.seriesIndexByType and added an example.
Using D3 range helpers to set position of RowSeries and ColumnSeries.
Merge branch 'tidyup' into remove-subseries

Conflicts:
	src/charts/Chart.js