cmnData<std::string>::SerializeText adds escape characters before spaces -- breaks some code

[pkazanzides]

cmnData<std::string>::SerializeText adds an escape character, '', before any spaces in the string being serialized. This breaks code in many argument constructors because they attempt to parse multiple parameters from a single string (in the FromStreamRaw method). This is only used by the cisstComponentManager, however, so it is not a major issue. My opinion is that we should preserve any escape characters already in the string, but not add any in SerializeText. We could have a separate method (perhaps a helper function) to add escape characters to a string.