* 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.