Add 32-bit/64-bit Java3D libraries to thirdparty/java3d

A separate 32-bit/64-bit install was done using
java3d-1_5_1-linux-{i586,amd64}.bin, and the two installs merged. (The lib/ext
folders in each install were identical.)
Create Java project

Using the "New Java Project" wizard in Eclipse.

Entries removed from the build path:
* STAC.jar
* uninstaller.jar
Add (64-bit Linux) SWT JAR to classpath so that project compiles
Changes to run STAC standalone

* bin should be on the classpath, not STAC.jar or src

* Java 3D JARs need to be on the classpath

* LD_LIBRARY_PATH needs to include the Java 3D libraries

* Allow additional VM arguments to be specified via JAVA_OPTS (useful for
  setting STAC_LOG_DIR)

STACDIR/BCMDEF/RUNDIR should be set prior to running runstac.sh. (If STACDIR
is unset, setupstac.sh sets it to the hard-coded value provided at install
time, which is undesirable. But if STACDIR is set, BCMDEF/RUNDIR aren't set
automatically.)
Add folder.gif to source tree

Copied from the pre-built STAC.jar. Was missing from the source tree after
installation.