Add cache directory underneath data.
Remove get_unsorted_events method because it isn't used.
Refactor event class.

-Remove get_formatted_message method because it isn't used.
-Refactored get_message to return a string instead of an array.
Refactor event_list class.

-Remove next method because it isn't used.
-Remove get_by_id method because it isn't used.
Refactor hangouts_reader class.

- get rid of begin rescue constructs
- fix logic when getting attachment links
- dump conversation if dump flat is set
- don't display conversation if dump flag is set
- clean file every time dump is executed
- check if participant name ist nil and set it to nameless
- skip conversation if it is not of the type regular_chat_message
- exit 1 if data file does not exist
Refactor participant list class.

- remove next method because it isn't used at all
extend main program.

- add pp for debugging purpose
- add dump flag to option parser
add .DS_Store to .gitignore .