Detect running timers, and stop a timer in ltl2tgba.
* src/misc/timer.hh (time_info::running): New attribute. (time_info::start, time_info::stop): Update and check time_info::running. * src/misc/timer.cc (timer_map::print): Mark running timers with a "+" in the output. * src/tgbatest/ltl2tgba.cc (main): Rename the name of the timers for SCC and simulation reduction, and actually stop the SCC timer.