specify java.home system property in GNU Classpath build
specify java.home system property in GNU Classpath build

Currently, we just set this to /tmp (or the equivalent) since Avian
doesn't really have a home.  This avoids a NullPointerException from
javax/xml/parsers/SAXParserFactory.

marcinolawski/avian,badlogic/avian,ucdseniordesign/avian,ucdseniordesign/avian,getlantern/avian,bigfatbrowncat/avian-pack.avian,dicej/avian,badlogic/avian,bgould/avian,minor-jason/avian,dicej/avian,badlogic/avian,MaartenR/avian,lwahlmeier/avian,bigfatbrowncat/avian-pack.avian,lostdj/avian,bigfatbrowncat/avian-pack.avian,dicej/avian,getlantern/avian,bigfatbrowncat/avian-pack.avian,lwahlmeier/avian,lwahlmeier/avian,getlantern/avian,marcinolawski/avian,MaartenR/avian,minor-jason/avian,joshuawarner32/avian,marcinolawski/avian,MaartenR/avian,lwahlmeier/avian,minor-jason/avian,joshuawarner32/avian,bgould/avian,marcinolawski/avian,lostdj/avian,badlogic/avian,joshuawarner32/avian,getlantern/avian,bgould/avian,lostdj/avian,lostdj/avian,ucdseniordesign/avian,MaartenR/avian,dicej/avian,ucdseniordesign/avian,joshuawarner32/avian,minor-jason/avian,bgould/avian