passFindCharacters should not throw compilation errors
passFindCharacters should not throw compilation errors

If multipass rules need to be validated, this should happen in
compilePassOpcode. The compilation error that was thrown in
passFindCharacters did not really make sense anyway.

Also fixed another issue in passFindCharacters.

BueVest/liblouis,BueVest/liblouis,liblouis/liblouis,hammera/liblouis,hammera/liblouis,liblouis/liblouis,liblouis/liblouis,BueVest/liblouis,BueVest/liblouis,hammera/liblouis,liblouis/liblouis,BueVest/liblouis,hammera/liblouis,liblouis/liblouis,BueVest/liblouis,hammera/liblouis,liblouis/liblouis,hammera/liblouis