Added support for fixed line height in the MultiLineTextWidget
Added support for fixed line height in the MultiLineTextWidget

When a fixed line height is set we need to compute the widget height in pixels based on font metrics. It is done by setting a different size policy which is driven by the sizeHint and minimumSizeHint.

boberfly/gaffer,appleseedhq/gaffer,ivanimanishi/gaffer,appleseedhq/gaffer,johnhaddon/gaffer,chippey/gaffer,boberfly/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,chippey/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,ImageEngine/gaffer,appleseedhq/gaffer,GafferHQ/gaffer,goddardl/gaffer,lucienfostier/gaffer,ivanimanishi/gaffer,andrewkaufman/gaffer,ivanimanishi/gaffer,johnhaddon/gaffer,chippey/gaffer,andrewkaufman/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,johnhaddon/gaffer,goddardl/gaffer,hradec/gaffer,goddardl/gaffer,johnhaddon/gaffer,boberfly/gaffer,lucienfostier/gaffer,appleseedhq/gaffer,hradec/gaffer,GafferHQ/gaffer,goddardl/gaffer,GafferHQ/gaffer,lucienfostier/gaffer,ImageEngine/gaffer,ImageEngine/gaffer,hradec/gaffer,ivanimanishi/gaffer,chippey/gaffer,boberfly/gaffer,hradec/gaffer,GafferHQ/gaffer,lucienfostier/gaffer,hradec/gaffer