#4 Patches to make installer work in CLI mode

[Darren Davison]

CLI mode fails (at least it does using 0.7.4 on
JDK1.5.0.06 / Linux-2.6.15 on my machines). This is
because of incomplete checking for headless environment
in a couple of classes.

The attached patch fixes this and should be fully
backward compatible, but I haven't tested on older
JDK's so YMMV.

We'd be grateful if this could be included in the tree
for antinstaller.

Cheers,

[Darren Davison]