Bug fix: can not seek in the area between buffer limit and capacity.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK8@1590707 13f79535-47bb-0310-9956-ffa450edef68
First version of support classes for DefaultFeature.


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK8@1590708 13f79535-47bb-0310-9956-ffa450edef68