clang3.7 build fix

```
clang++ -pipe -std=c++11 -g -O0 -DDEBUG -c -Wall -pedantic -Wextra -Werror -fPIC -I/home/tomas/zdrojaky/automata-library/alib2data/src/../../alib2std/src/ -I/usr/include/libxml2/ /home/tomas/zdrojaky/automata-library/alib2data/src/automaton/Automaton.cpp -o /home/tomas/zdrojaky/automata-library/alib2data/obj-debug/automaton/Automaton.o
/home/tomas/zdrojaky/automata-library/alib2data/src/automaton/Automaton.cpp:20:11: error: redundant move in return statement [-Werror,-Wredundant-move]
                        return std::move(nextState);
                               ^
/home/tomas/zdrojaky/automata-library/alib2data/src/automaton/Automaton.cpp:20:11: note: remove std::move call here
                        return std::move(nextState);
                               ^~~~~~~~~~         ~
1 error generated.
```

```
clang++ -pipe -std=c++11 -g -O0 -DDEBUG -c -Wall -pedantic -Wextra -Werror -fPIC -I/home/tomas/zdrojaky/automata-library/alib2algo/src/../../alib2str/src/ -I/home/tomas/zdrojaky/automata-library/alib2algo/src/../../alib2data/src/ -I/home/tomas/zdrojaky/automata-library/alib2algo/src/../../alib2std/src/ -I/usr/include/libxml2/ /home/tomas/zdrojaky/automata-library/alib2algo/src/automaton/transform/Compaction.cpp -o /home/tomas/zdrojaky/automata-library/alib2algo/obj-debug/automaton/transform/Compaction.o
/home/tomas/zdrojaky/automata-library/alib2algo/src/automaton/transform/Compaction.cpp:56:24: error: moving a temporary object prevents copy elision [-Werror,-Wpessimizing-move]
                while((transitions = std::move(automaton.getTransitionsFromState(q))).size() == 1 && automaton.getFinalStates().count(q) == 0) {
                                     ^
/home/tomas/zdrojaky/automata-library/alib2algo/src/automaton/transform/Compaction.cpp:56:24: note: remove std::move call here
                while((transitions = std::move(automaton.getTransitionsFromState(q))).size() == 1 && automaton.getFinalStates().count(q) == 0) {
                                     ^~~~~~~~~~                                    ~
```

See merge request !12