doc/guide/kea-logo-100x70.png
	new file, it it the Kea logo with the bird's head only

doc/Doxyfile
    Changed PROJECT_LOGO to use use new Kea logo

doc/Makefile.am
    Added logo file to dist_html_DATA so it will be installed

doc/guide/kea-guide.xml
    Added logo as inlinemedia object to the title