Support for installation of glibj.zip and separate class files

[Michael Koch]

Hi all, 



With my big NIO commit I accidently commited the first part (the parts 
in configure.ac) for this patch and so I decided to commit it fully.
We now have two options for installing our classes

--enable-glibj
installs glibj.zip (enabled by default)

--enable-class-install
installs all classes as separate files as needed by jamvm and sablevm 
(disabled by default)

Both options are indepedently from each other. You can even disable both 
options but this does not make really sense.

I'm not really satisfied with the name "--enable-class-install". If 
someone finds a better name please shout at me.


Michael