basic notions string revised

alib2/src/alphabet/Epsilon.cpp

alib2/src/automaton/FSM/EpsilonNFA.cpp

alib2/src/automaton/FSM/EpsilonNFA.h

alib2/src/string/CyclicString.cpp

alib2/src/string/CyclicString.h

alib2/src/string/Epsilon.cpp

alib2/src/string/Epsilon.h

alib2/src/string/MutableString.cpp

alib2/src/string/MutableString.h

alib2/src/string/String.cpp

alib2/src/string/String.h

alib2/src/string/StringFromXMLParser.cpp

alib2/src/string/StringFromXMLParser.h

alib2/src/string/StringParser.cpp