* bin/common_conv.cc, bin/common_conv.hh: Here.
* bin/autfilt.cc, bin/common_trans.cc, bin/ltlcross.cc, bin/ltldo.cc,
bin/ltlfilt.cc, bin/ltlgrind.cc, bin/randaut.cc, bin/randltl.cc: Pass
the name of the argumennt to the conversion function.
* tests/core/ltlcross3.test, tests/core/ltldo.test,
tests/core/randaut.test: Add test cases.