[Xcb] Use of C++ keyword 'class'

[Ulrich Eckhardt]

Hi!

In xcb_icccm.h, in struct xcb_get_wm_class_reply_t, there is a field 
called 'class', which is a valid identifier in C but a reserved keyword in 
C++. Could that be changed to e.g. 'class_name' or 'type'?

Thanks!

Uli