This patch adds the two color-settings selectionfg and selectionbg to config.def.h. Those define the fore- and background colors which are used when text on the screen is selected with the mouse. This removes the default behaviour which would simply reverse the colors.

Additionally, a third setting ingnoreselfg exists. If true then the setting selectionfg is ignored and the original foreground-colors of each cell are not changed during selection. Basically only the background-color would change. This might be more visually appealing to some folks.