Generalize StreamBuffer and BufferReader consumers

[andeaseme]

Identify common design patterns from example usage. Currently there are a couple different examples:

1. Consumers using a single source for a single purpose
2. Consumers using two sources. One source is watched for events to perform actions with the other source.

All my examples have been asynchronous (using threading) as the intent is to have modular components that are independent and unblocked by unrelated processes BUT I'm sure there are good examples of synchronous code that should be considered. Incorporate these and other combinations you can think of.

The generalization could an abstract class that minimizes common boiler plate or help construct something a bit more specific but still common like trigger based events. Ideally, this will be one simple thing to handle everything but more likely will be one base plus a few others to cover a wide range of common patterns.

Best to work on this if you've created an example yourself.

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