Merge branch 'master' into interface
Changed classpath and added ANTLR lib

To support natural language parsing of dates from user.
Merge branch 'master' into interface

Conflicts:
	.classpath
Integrated mark command and NLP for date parsing

- Mark is now an acceptable CommandType and parsed.
- Natural language for date is supported for parsing
Merge branch 'master' into interface
Merge branch 'interface'