Updated default title theme

Applied the theme properly to chart titles
Added titlePadding variable
Merge pull request #188 from niksoper/develop

Updated default title theme
Added filterChanged method

Acts as an event that can be used to notify the client that filtering has changed in some way on a ChartGroup.
Reduced opacity of 'notselected' points

This makes it clearer which bubble has been highlighted on a bubble chart.
Merge pull request #189 from niksoper/develop

ChartGroup filterChanged
Merge branch 'upstream' into develop
Update License year/name
Merge pull request #193 from tpkelly/develop

Update License year/name
Merge remote-tracking branch 'scottlogic/develop' into feature/tick-frequency
Update changelog