we want to make sure we are alligned with master now
we don't need to use the libxml2 that comes with it
add libxml2 as a dependency now, use master branch, simplify darwin depencies
add libxml2 as dependency, comment out darwin section because the default class should be used
we don't need this when we use the gub libxml2
upgrade to version 2.8.0
we don't need this when we use the gub libxml2
upgrade to lilypond 2.16.2
we don't need this when we use the gub libxml2
add libxml2-devel as a dependency