added some NTL/STL compatibility functions
added some NTL/STL compatibility functions

shaih/HElib,AlexanderViand/HElib,berserkr/HElib,shaih/HElib,AlexanderViand/HElib,AlexanderViand/HElib,shaih/HElib,berserkr/HElib,berserkr/HElib