Move request_take_focus to window-x11

This will let us kill off send_icccm_message
Move send_icccm_message to window-x11
window: Remove support for colormaps

While the ICCCM mandates the use of this, it's not necessary under
a composited environment from my understanding, and it's a flat
out no-op under XWayland.

Looking at the other rootless servers like Xwin/Xquartz, it seems
that they contain code for colormap emulation, but they're actually
never used -- a bug prevents the code from ever being called. Given
that it's been this way since 2003, I'm going to hazard a guess that
not many apps using colormaps. Kill them off.