Remove pointless "target library" chapter.

It had a very little bit of content; move that to the more extensive
chapter on config file guidelines, and give more current "ls" output
to show the available library code.


git-svn-id: svn://svn.berlios.de/openocd/trunk@2820 b42882b7-edfa-0310-969c-e2dbd0fdcd60