attack_analysis can take strategy passed from the config of aspect_attack

Detail:
1. the constructor of attack_analysis is overloaded to accept a
possible config parameter
2. the supposed config file format is like
[analysis_strategy]
  [target_analysis_strategy]
    name=strategy1
  [/target_analysis_strategy]
  [attack_analysis_strategy]
    name=strategy1
  [/attack_analysis_strategy]
[/analysis_strategy]
3. aspect_attacks parse the config file in constructor and save it.
attack_analysis can read from it later
4. improved a few namings
5. add log to set_strategy method so that we know default strategy is
applied