Bug 298835 Merge e4 Project Path Variable back into the 3.6 stream
The virtual folder and filters changes are already in 3.6, the project path variable changes in e4 still remains to be merged.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/PathVariableDialog.java
*/
    private void selectFolder() {
        DirectoryDialog dialog = new DirectoryDialog(getShell(), SWT.SHEET);
        dialog.setText(IDEWorkbenchMessages.PathVariableDialog_selectFolderTitle);
        dialog.setMessage(IDEWorkbenchMessages.PathVariableDialog_selectFolderMessage);
        String filterPath = getVariableResolvedValue();
        dialog.setFilterPath(filterPath);
        String res = dialog.open();
        if (res != null) {
            variableValue = new Path(res).makeAbsolute().toOSString();
            variableValueField.setText(variableValue);
        }
    }
    /**
     * Opens a dialog where the user can select a file path.
     */
    private void selectFile() {
        FileDialog dialog = new FileDialog(getShell(), SWT.SHEET);
        dialog.setText(IDEWorkbenchMessages.PathVariableDialog_selectFileTitle);
        String filterPath = getVariableResolvedValue();
        dialog.setFilterPath(filterPath);
        String res = dialog.open();
        if (res != null) {
            variableValue = new Path(res).makeAbsolute().toOSString();
            variableValueField.setText(variableValue);
        }
    }
    private void selectVariable() {
        PathVariableSelectionDialog dialog = new PathVariableSelectionDialog(
                getShell(), IResource.FILE | IResource.FOLDER);