Initial commit of XCB components

Hi,
here is an initial commit of the XCB components. 
Since alanc pointed me to the xnv-gate I found that facet.devel=true is applied to a header files and xml files in:

https://hg.java.net/hg/solaris-x11~x-s12-clone/file/8028b18c77b1/pkg/manifests/x11-library-libxcb.p5m

Should I enforce the same attributes ?
Also I am not sure how to enforce build dependencies.
Thank you for your help and comments.
Best regards,

Aurelien