Rearrange the UI to resemble top

Moved the graphs below the toolbar and made them taller, so that they
are more readable/usable. Converted the statusbar into a box, moved it
below the graphs and rearranged the content to match the graphs.
Pack the searchbox into the toolbar
Draw CPU and Mem graph in different colors
Make CPU and Mem labels use the graph colors
Tone down the colors in the treeview