The current insensitive style for buttons needs to be improved. Right
now we just change the text color: this doesn't make it clear that the
button is actually insensitive.
Instead of just changing the text color, we make the button background
almost transparent. We also make the text color the same as the border
color, use a thinner border.
This patch also simplifies some border rule overwrites to emphasis
only the border width is changed on focus, and makes the button look
closer to the mockups.
https://bugzilla.gnome.org/show_bug.cgi?id=687110
37d6a624b7
