[BoostXmlCndInterface] Changed sig. of virtual Writer::write().
[BoostXmlCndInterface] Made reading/parsing of geometry tag xml more clear.
[BoostXmlConditionInterface] Added CondType _type to decide what type of condition should be written.
[BoostXmlCndInterface] explicit to constructor.
[BoostXmlCndInterface] Removed most of the write() method.
[BoostXmlCndInterface] Test functionality.
[BoostXmlGmlInterface] Removed parameter name to fix warning.