Version 0.7.0

Adds introspection tools for channel management objects:
- get_channelmethods
- get_channelproperties
Changes logger names for artifacts and downgrades some messages from INFO level to DEBUG
- This change in logger names could break deployed logging configurations, and for this reason, we incremented the minor version; otherwise this would be a micro bump.

Version 0.6.0

Adds the channelmethod decorator as a callable-oriented version of channelproperty (Issue #41)
Includes ipython notebook user guide (thanks to Patrick Rusk!)
Suppresses the "future exception not handled" warnings from tornado for channels. (Issue #30)

Adds the new flowz.channels.tools module for utility functions/helpers that extend the flexibility of channels without expanding the core interface.
Adds rolling window functionality therein.

Removes (silently) deprecated targets classes and tests
- Including support within the flowz.app.Flo class
Downgrades some logging messages to DEBUG level
Changes some keyword parameters on windowby/groupby (from keyfunc on both to keys_func and key_func, respectively).

Windowing and grouping: WindowChannel, GroupChannel, windowby(), groupby()
Chaining: ChainChannel, chain()
Observing channels for side-effects: ObserveChannel, observe()
Improved exception handling within channels, to ensure traceback is properly captures. Note that this is python-2 oriented, and will need to be revisited for python 3.
Added some channel utility functions: channel_join, merge_keyed_channels, incremental_assembly
Some additional unit testing improvements

Artifact classes added.
Channel management tools (channelproperty decorator, ChannelManager class, etc.)
Rearranged flowz.channels from a module to a subpackage.