refactor trees

alib2algo/src/automaton/run/Accept.h

alib2algo/src/automaton/run/Occurrences.h

alib2algo/src/automaton/run/Result.h

alib2algo/src/tree/generate/RandomTreeFactory.cpp

alib2algo/src/tree/generate/RandomTreeFactory.h

...2data/src/regexp/unbounded/UnboundedRegExpAlternation.cpp

...ata/src/regexp/unbounded/UnboundedRegExpConcatenation.cpp

alib2data/src/tree/RankedTree/RankedNode.cpp

alib2data/src/tree/RankedTree/RankedNode.h

alib2data/src/tree/RankedTree/RankedTree.cpp

alib2data/src/tree/RankedTree/RankedTree.h

alib2data/src/tree/TreeFromXMLParser.cpp

alib2data/src/tree/TreeFromXMLParser.h

alib2data/src/tree/TreeToXMLComposer.cpp

alib2data/src/tree/TreeToXMLComposer.h

alib2data/src/tree/UnrankedTree/UnrankedNode.cpp

alib2data/src/tree/UnrankedTree/UnrankedNode.h

alib2data/src/tree/UnrankedTree/UnrankedTree.cpp

alib2data/src/tree/UnrankedTree/UnrankedTree.h

alib2data/src/tree/common/RankedAlphabet.cpp