Remove the hb-view utitilty from the main harfbuzz port and move it to it's
own port. The hb-view utility is the only part of harfbuzz that requires
cairo. So now harfbuzz doesn't pull in x11 libraries or mesa via cairo,this
is usefull for ports that want to use harfbuzz but don't use or want x11.
Exp-run by: antoine@