changing to new orbit s-build and reverting batik-version to 1.6

- parts of eclipse e4 platform use 1.6 and scout wouldn't be compatible if it used 1.7
Bug 391198 - RAP 2.0 Migration to Eclipse Scout 3.9

Re-organize imports due to package name changes
Changes deprecated constant from WidgetUtil.CUSTOM_VARIANT to RWT_CUSTOM_VARIANT
Changes for RAP 2.0 according to Migration Guide
Adjust Target Files for Eclipse 3.6 - 3.9
Set batik-version to minimum 1.6.0
Javadoc modification