Introducing commulative acks
Improved cummack structure
Re-worked cummacks to introduce distant ranges
Demonstrate SSKs for which deriving the insert URI does not work:
- I am not yet certain whether it should work in this case. It breaks stuff in WOT as it is at the moment.
Added backwards compatibility by means of negType
Actual negType definition
Updated unit tests to a new ack format
Yet another unit-test update
Indent.
Javadocs and indenting.
Fix fd leak
Merge remote-tracking branch 'quadrocube/transport-layer-modifications' into cumulative-acks

Conflicts:
	src/freenet/node/FNPPacketMangler.java
Catch more specific exception.
Check packet size when adding acks.
Add more unit tests.
Simplify code slightly.
Check length, this should pick up some subtle bugs.
Check a single range.
Remove bogus Math.abs()
Fix bogus assertion I introduced in 5456e6401726900052b9e0f8a219798862fdaf86