Renamed log_sum_date.awk to log_sum_time.awk.

Fixed a bug in log_sum_c.awk where the result limit did not work properly.
Removed function tst() from log_sum_c.awk since it wasn't used.
Implemeneted support for flag 2. Due to problem with passing arguments in awk the syntax s=1 needs to be used to call 2.
Started working on flag r. It doesn't work properly yet.