[#1453] Better traceback

Adding         
 attempt = "".join(self.buflist)
somewhere close to the end of the TAL.TALInterpreter.FasterStringIO.write() reveals better stacktrace:

Traceback (innermost last):
  Module ZPublisher.Publish, line 115, in publish
  Module ZPublisher.mapply, line 88, in mapply
  Module ZPublisher.Publish, line 41, in call_object
  Module Products.ZWiki.Views, line 710, in editform
  Module Products.ZWiki.Views, line 731, in editform
  Module Shared.DC.Scripts.Bindings, line 311, in __call__
  Module Shared.DC.Scripts.Bindings, line 348, in _bindAndExec
  Module Products.PageTemplates.PageTemplateFile, line 113, in _exec
  Module Products.PageTemplates.PageTemplate, line 104, in pt_render
   - <PageTemplateFile at /isoc/wiki/editform used for /isoc/wiki/PrawoPrasowe>
  Module TAL.TALInterpreter, line 238, in __call__
  Module TAL.TALInterpreter, line 281, in interpret
  Module TAL.TALInterpreter, line 749, in do_useMacro
  Module TAL.TALInterpreter, line 281, in interpret
  Module TAL.TALInterpreter, line 457, in do_optTag_tal
  Module TAL.TALInterpreter, line 442, in do_optTag
  Module TAL.TALInterpreter, line 437, in no_tag
  Module TAL.TALInterpreter, line 281, in interpret
  Module TAL.TALInterpreter, line 772, in do_defineSlot
  Module TAL.TALInterpreter, line 281, in interpret
  Module TAL.TALInterpreter, line 542, in do_insertText_tal
  Module TAL.TALInterpreter, line 839, in write
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc5 in position 56: ordinal not in range(128)


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forwarded from http://zwiki.org/1453AnotherUnicodeDecodeErrorDuringEditPreview#[email protected]