fix all instances of log.err() that take just a string as an argument.

New submission from jesstess <[email protected]>:

log.err() is called with just one string all over the place even though the first parameter, _stuff, is type: NoneType?, Exception, or Failure according to the docs. Say the docs, _stuff "will be wrapped in a Failure". However:

from twisted.python import failure
failure.Failure("Test")
main__:1: DeprecationWarning?: Don't pass strings (like 'Test') to failure.Failure (replacing with a DefaultException?).
<twisted.python.failure.Failure <class 'twisted.python.failure.DefaultException?'>>

so to skirt the DeprecationWarning and future unwanted behavior something else needs to be done with the strings to these log.err instances.

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Type     : defect
Component: core
Keywords : 
Priority : normal
Nosy     : jesstess
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http://twistedmatrix.com/trac/ticket/3996