Changeset 6 for trunk/lib/library.xml

Fixed the Tcl library to mirror the API developed for XML
libraries on the Python side. The Tcl Rappture::library
now has methods like "children", "element", "put", etc.
One difference: On the Tcl side, the default -flavor for
element/children is "component", since that works better
in Tcl code. In Python, the default is flavor=object.

Also fixed the Tcl install script to install not just
the tcl/scripts library, but also the ../gui and ../lib
directories.