Merge pull request #13 from boegel/graphviz_with_perl_binding

sync with develop & resolve conflict
GObject-introspection added for GNOME
Merge branch 'graphviz_with_perl_binding' of github.com:hajgato/easybuild-easyconfigs into graphviz_with_perl_binding
cairo bumped to 1.12.18
disable symbol lookup in cairo