retinaDisplay is overwriting my explicit styling

[andersponders]

Chart.js/src/core/core.helpers.js

Line 547 in b64fd5d

canvas.style.height = height + 'px';

The comment attached to line says "if they are not set" lets use the render size as the display size but theres no conditional here, its just setting them every time over my existing style options

[Ejdamm]

This bug makes the usage example broken http://www.chartjs.org/docs/latest/getting-started/usage.html and also here http://www.chartjs.org/docs/latest/
It might scare some new users off when not even the example code works.

[etimberg]

Done in #4874