add descriptions to #endif directives in turblib.h
add descriptions to #endif directives in turblib.h

since the #ifdef/#endif blocks are so long, I think this should be the
standard...

git-svn-id: 78680c43735c8fc1bfd988e787ae5b6171b14100@10983 743f73a2-0892-4f1a-8574-ff7a07c3af4f

idies/turblib,idies/turblib,idies/turblib