[Xcb] xcb unit tests

[Trevor Woerner]

Prior to my exposure to xcb about a month and a half ago, I wasn't aware 
of the "check" unit test facility. Since then I've been using it quite 
extensively. As you probably know, "check" can be configured to 
generate an XML log file. I've written an XSLT stylesheet for 
transforming that output into a decent HTML page complete with 
different colours to indicate individual test result status.

Anyone interested?

I've found that if a test fails I generally want "make" to keep going so 
the HTML test result page will get generated. For this to occur I use 
the "-k" flag when doing a "make check". Since I'm specifying the "-k" 
flag I prefer to have the unit tests performed in a directory different 
from that of the sources themselves. That way I can _not_ specify the 
"-k" flag when building xcb itself; making it easier to catch compile 
errors with the library. Is there any interest in moving the unit tests 
to a different directory? I'd be happy to do this, but I wouldn't know 
how to submit a diff for this.

I'd also be happy to modify the build system to automatically generate 
the HTML results page as part of any "make check".

I hope I'm not stepping on anyone's toes by making these suggestions.