Deprecate BasicDoFn
Implement DList equality (#190)
Some clarity changes to DList isEqual
Improve the performance of DList.isEqual

This is achieved by avoiding duplicating the Key, which could
potentially be a very large type.

The more obvious way of doing this would be to use an Int, where
all the lefts are -1 and all the rights are +1. And then use .sum
== 0 to make sure there is the same amount. This indeed is even
faster than the approach here, but suffers a fatal flaw -- it can
overflow giving a false equality.

Using longs on the other hand is elegant, but is not very space
efficient. So this approach uses and booleans and does the count
using a long.
added more debug logs
initialised a value to an empty list
updated the scala version to 2.10.1
added some default values for the bridgestore variables
not showing the computation graph unless showgraph is passed on the command line
removed the ugly bridgestore hack to see if it is necessary at all
better display of the mappers for input channels
do not display last mappers if there are no mappers
better display of nodes sinks
connected the command-line arguments to the configuration properties (but just for the showgraph argument)
fixed the layers creation when the root of the tree is a selected node
added some unit tests for the layers fix when a ParallelDo is the last node of the graph
displaying all examples in the travis build
trying to run travis with more memory
added semigroup as a Reduction instance
added some examples of command-line arguments which can be used to run Scoobi specifications. fixes #227