Better debugging tools for viewing state of Deferreds

New submission from jml <[email protected]>:

Deferreds can be quite tricky to debug. Twisted should provide tools for programmers that inspect the state of a Deferred and report it in a meaningful way.

Although graphical output would be nice, we can consider this ticket closed when we have a function that dumps some text for a Deferred that includes:
  * whether the Deferred is paused
  * whether the Deferred is running
  * the callback chain
  * the current value
  * whether the Deferred is waiting on another


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Type     : enhancement
Component: core
Keywords : 
Priority : normal
Nosy     : 
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http://twistedmatrix.com/trac/ticket/4304