Speed-up log analyze

Remove dependancy on boost date_time functions.
Keep response time & size in DB, preparation for #7
Add size/duration and a few other things

- Store responses Size and Duration in DB
- Add a new thread to concat reponses sizes/durations in DB
- Use a ThreadPool with C++11 lambdas to run with as much thread as
logical cores are availables
- Remove logging on bdb
- Add a progress bar on insert
- Change DEBUG logs activation in makefile
- Optimize a little bit of code arround line analyse
- Change to uint64_t in case of huge logs files