KDE Release Service 19.12.0

• Restore “Show ‘new tab’ button” option in Konsole Settings.
• Do not allow duplicate bookmarks to be added, currently only works in top folder.
• For color schemes that use random colors, randomize the colors using HSLuv color space instead of HSL. It has perceptually uniform lightness, which means every color with the same lightness value is perceived as equally bright by humans.
• Replace environment variable KONSOLE_PROFILE_NAME with dbus method profile().
• Fix issue that applying settings in Configure Konsole dialog was causing every Konsole window to be hidden and shown again.
• When building Konsole, use ccache if found.