added support for filter tag
Merge pull request #93 from dustins/filter2

Feature: Support for filter tag
render method of Content interface now receive a RenderStream instead of OutputStream
working concurrent feature
Fixed broken tests
added cancel of tasks when giving error on rendertask
added new option blocked to not allow closing of the outputstream on the singleoutputstream
Optimized to the most left childrens of the outputstream tree to always use the default outputstream
added a faster implementation of the ByteArrayOutputStream
Merge branch 'origin/master'