Bug 110331 add tests for import/export
I have written additional tests for import archive, export to file system and export to archive. And changed the import existing and import operation (file system) tests. This work required a change to the TarFile class in the ide plugin. Attachments to follow.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/TarFile.java
* 
	 * @return enumeration of all files in the archive
	 */
	public Enumeration entries() {
		return new Enumeration() {			
			public boolean hasMoreElements() {
				return (curEntry != null);
			}
			
			public Object nextElement() {
				TarEntry oldEntry = curEntry;
				try {
					curEntry = entryEnumerationStream.getNextEntry();
				} catch(TarException e) {
					curEntry = null;
				} catch(IOException e) {
					curEntry = null;
				}
				return oldEntry;
			}
		};
	}
	/**
	 * Returns a new InputStream for the given file in the tar archive.
	 * 
	 * @param entry
	 * @return an input stream for the given file
	 * @throws TarException
	 * @throws IOException
	 */