I have slightly changed it to better match map/reduce paradigm
described here http://labs.google.com/papers/mapreduce.html
Therefore, we now have both map/reduce and a more simple "execute
this task unit on remote nodes and return results" proposal.
Users might not like number of type parameters in MapReduceTask. I
wanted to be as precise as possible to begin with and we can discuss
how and if to reduce them.
Example for map/reduce is WordCountExample.java. Have a look.
I put a proposal in distexec package. I wanted to have parent
package to branch from. We need to accommodate simple execution
model, map/reduce, various execution policies and so on. They could
not fit all in mapreduce package and its children. Hence distexec
package. If you think you have better name - speak up.