[LITMUS^RT] web and code updates

[Björn Brandenburg]

Hi everyone,

a few updates. On the code front, I’ve pushed a few patches to the kernel that improve the tracing support to make it easier to find in the config, and to allow Feather-Trace work also with read-only text segments. Further, I’ve restructured the TRACE() debug tracing header a bit to avoid clashing with similarly named symbols in unrelated parts of the kernel. 

Regarding the web site, many thanks to Nathan Otterness (of UNC) for updating the “how to write a plugin” tutorial to the latest kernel, and for generally helping  a lot with updating the web page. Go check out our new documentation overview!

	http://www.litmus-rt.org/documentation.html

Updates and fixes are very welcome: to edit the web page, just fork the repo (https://github.com/LITMUS-RT/www.litmus-rt.org) and send a pull request on GitHub. 

Thanks,
Björn