Add proper coloring for panel and window list in Cinnamon

[tre-flip]

I've made cinnamon panel look closer to the panel from GNOME2. So far only for the default color variant. Please, let me know what you think?

Before:

After:

[luigifab]

Yes it's so better.
For reference: gtk3 mate desktop.

For colors you can write for example:

	color: #AAA; /* @menuitem_hover */
	border: 1px solid #AAA; /* @menuitem_hover_border */
	background: linear-gradient(to bottom,
		/*  @menuitem_hover_glaze_top */ #AAA,
		/* @menuitem_hover_glaze_mida */ #AAA 50%,
		/* @menuitem_hover_glaze_midb */ #AAA 50%,
		/*  @menuitem_hover_glaze_bot */ #AAA);
	background-gradient-start: #AAA; /* @menuitem_hover_glaze_top */

Then run bash .../src/colors-cinnamon.sh Human to update colors in src/Human/cinnamon/cinnamon.css from gtk files (for example #AAA to #FFFFFF for @menuitem_hover).

Run bash .../src/colors-cinnamon.sh to update all colors variants based on the default variant.