simplify dispatch and error reporting

aconvert2/src/DotConverter.cpp

aconvert2/src/DotConverter.h

aconvert2/src/GasTexConverter.cpp

aconvert2/src/GasTexConverter.h

aconvert2/src/TikZConverter.cpp

aconvert2/src/TikZConverter.h

alib2algo/src/arbology/exact/BadCharacterShiftTable.cpp

alib2algo/src/arbology/exact/BadCharacterShiftTable.h

alib2algo/src/arbology/exact/BorderArrayNaive.cpp

alib2algo/src/arbology/exact/BorderArrayNaive.h

...algo/src/arbology/exact/ExactPatternMatchingAutomaton.cpp

alib2algo/src/arbology/exact/ExactPatternMatchingAutomaton.h

alib2algo/src/arbology/exact/ExactSubtreeAutomaton.cpp

alib2algo/src/arbology/exact/ExactSubtreeAutomaton.h

...algo/src/arbology/exact/ExactSubtreeMatchingAutomaton.cpp

alib2algo/src/arbology/exact/ExactSubtreeMatchingAutomaton.h

alib2algo/src/arbology/exact/ExactSubtreeRepeatsNaive.cpp

alib2algo/src/arbology/exact/ExactSubtreeRepeatsNaive.h

alib2algo/src/arbology/exact/ExactTreePatternAutomaton.cpp

alib2algo/src/arbology/exact/ExactTreePatternAutomaton.h