DarkNight theme for Ghidra

There are still some "bugs" in the display, because actually we can't configure colors for everything :

colors in the Symbol Tree window (function names are hard to read)
background decompilation window when the cursor is in an undefined function
selection in decompilation mode
PCode
graph window

To install the theme, run the script :

./set_colors.py ~/.ghidra/.ghidra-9.0/tools/_code_browser.tcd