Projucer: Change ComboBox outline colour to TextButton outline colour

[andrew-kwon]

Hi ROLI,

When I create a TextButton component in GUI, the TextButton outline doesn't equal preview in Projucer.

I think it is because LookAndFeelV4 use ComboBox::outlineColourId in drawButtonBackground (..) .

So firstly I added TextButton::outlineColourId in juce_TextButton.
And I revised some code to change button's outline in Projucer directly.

Please let me know if something is wrong.

Thanks,

Andrew Kwon.