Rpqueue

[fixed] actually apply cron task fix :P

[fixed] cron tasks will now save the results of their execution if requested,
the argument to make this happen was mistakenly not passed onto the class
that handles all of this. Thank you to github user
https://github.com/jpassaro for the bug report and PR
[added] the ability to use a "prefix" to allow namespacing of rpqueue queues
on the same Redis server. See `rpqueue.set_prefix()`
[added] the ability to instantiate a new rpqueue "state", for running parallel
task execution systems with different prefixes, connections, etc. See
`rpqueue.new_rpqueue(name, pfix=None)`
[added] warning-laced support for Python 3.x. The tests pass :P

[added] the ability to call a single function after worker processes have been
created. `import rom; rom.AFTER_FORK = fcn` - put this in the same module
that imports all of your tasks (the module referred to in --module), and
the function will be run in the newly forked child, just prior to starting
worker threads

[changed] forced a hard requirement on the Redis client to be 2.4.12 or later
to remove the unnecessary thread/fork-safe pooling. The Redis client has
been thread/fork safe since 2.4.12 (though got better multiple thread
post-fork support in 2.9.0)
[changed] added rpqueue.set_redis_connection() for manually setting additional
options (note that you can also just say `rpqueue.POOL = conn`)

[added] --loglevel and --successlevel to set the minimum log level to print
and the log level that "SUCCESS: Task completed:" messages are sent at
when using `python -m rpqueue.run ...` invocation. Initial patch thanks
to: https://github.com/zenweasel
[added] when running rpqueue via `rpqueue.execute_tasks()`, you can set the
log level and success log level (--loglevel and --successlevel, mentioned
above) via setting the rpqueue.LOG_LEVEL and rpqueue.SUCCESS_LOG_LEVEL
attributes to one of: 'DEBUG', 'INFO', 'WARNING', or 'ERROR' .
[updated] the Lua script runner wrapper we use for delayed task execution to
be cleaner.

[fixed] setup.py-based installations. Ran into the bug myself :/