Remove reducer code.
Add command queue for mappers to signal them to exit cleanly
Move Daemon role to Process class and add non-blocking option for Mapper
Implement max_iterations for processes.  Improve redis key cleanup, especially if a mapper fails
Inputs for each job now go into different lists and mappers work on random items
Implement max_memory for processes
add .hgignore
Fix a case where mr-commands list was not being cleaned up after a mapper exited.
Clean up inputs list when mapper process exits
Increment version to 0.300
Improve process cleanup.  Make mapper in main process optional.  Inputs will be put back in the queue if there is no mapper.
Add a timeout for waiting on results and increase the time to wait for a mapper process to exit before terminating it with KILL
Try to clean up mapper process before checking to see if it is still running
Fix cleanup tests to destroy MapReduce object before checking that its keys were cleaned up.
Mappers will clean up jobs where the requester has aborted
mapreduce process manager and script