The PROJECT_LOGO field is now used to include the XZ logo. The footer
of each page now lists the copyright information instead of the default
footer. The license is also copied to statisfy the copyright and so the
link in the documentation can be local.
When the docs are installed, calling the directory "liblzma" is
confusing since multiple other files in the doc directory are for
liblzma. This should also make it more natural for distros when they
package the documentation.
Instead of having Doxyfile.in configured by Autoconf, the Doxyfile
can have the tags that need to be configured piped into the doxygen
command through stdin with the overrides after Doxyfile's contents.
Going forward, the documentation should be generated in two different
modes: liblzma or internal.
liblzma is useful for most users. It is the documentation for just
the liblzma API header files. This is the default.
internal is for people who want to understand how xz and liblzma work.
It might be useful for people who want to contribute to the project.