cinnamon-settings: When switching between normal and advanced modes while
inside a panel, resize the window accordingly.
Perform a slight fade-in when showing cinnamon settings.  The reason for this
is, when calling a panel directly (i.e. cinnamon-settings sound) you can sometimes
see the full window/icon view first before it switches to the selected panel
and the window resizes.  Unfortunately, to calculate the resizes properly, we have
to 'show' the window so all its children are sized up and realized.

This is a bit of a trick, starting the window fully transparent, and only
turning opaque once everything is loaded.
set glade opacity to 0
simplify some code
Tweak fade in a bit faster, smoother
cinnamon settings: Improve look of keyboard page a bit
Merge pull request #1880 from mtwebster/mode_switch_resize

cinnamon-settings: When switching between normal and advanced modes while inside a panel,