Fix: If $XDG_DATA_HOME doesn't exist, create it.
Create empty event file at startup in necessary
Add test: event sequence with multiple stops
Revamped CLI parsing

Arg parser rewritten with CmdArgs.Explicit
New report args supported (refs #6 )
Add: Reports structure + TotalTime report
Add: Filtering support in report generation

Filter by project, activity or tag
Add version information
Merge pull request #9 from divarvel/basic-cli

Switch to CmdArgs.Explicit