Fix images installation
Software shadow for buttons

Buttons now stand out much better.
ButtonStyle: seamless transition between normal and pressed

Make the transition faster.
ButtonStyle: increase implicitHeight

Label is now much more readable.
ButtonStyle: set radius to 5

Looks much better this way.
ButtonStyle: increase padding between label and background

Also decrease implicitHeight a little bit to not make buttons taller.
ButtonStyle: make it look like more tridimensioanl

Improve the linear gradient to give a more tridimensional look.
ButtonStyle: change animation on opacity

OutSine curve.
ButtonStyle: text color to #333333

Makes a better contrast.