updated license information

git-svn-id: https://dev.geogebra.org/internal/moodle/moodle-repository_geogebratube/trunk@3400 872ce066-4876-4fca-a6fc-23b94bf576d1
Merged from trunk
updated license information [from revision 3399]

git-svn-id: https://dev.geogebra.org/internal/moodle/moodle-repository_geogebratube/branches/MOODLE_27_STABLE@3402 872ce066-4876-4fca-a6fc-23b94bf576d1