Commit 5bbe37467954056c8366f063322df3af64d76ab0

When renaming, make sure not to delete records if the new and old names are identical
  
444444 if oldColumn not in self:
445445 raise KeyError, unicode("Unknown column")
446446
447 # Bail out gracefully if the names are equal
448 if oldColumn == newColumn:
449 return
450
447451 for index, column in enumerate(self.columns):
448452
449453 if oldColumn == column:
486486
487487 final_matrix = args.pop(0)
488488
489 for item in args:
489 for index, item in enumerate(args):
490490 assert isinstance(item, DataMatrix), "Not a valid DataMatrix isntance"
491491 final_matrix = _cbind(final_matrix, item)
492492