Change wording of err_required string
Implement help functionality

Add .help function to print help screen
Add showHelp property for opts for automatically invoking help on specific params
Update README.md

Add .help documentation.
Update CHANGELOG.md

0.3 changelog
Bump version to 0.3.0
Refactor .help function
Add Obj.reduce function

Reimplement getArgumentsWidth_ using Obj.reduce
Help banner variable replacing

Add variable replacing for help banner string
Replace REQ_OPTS with required options in banner string
Add more keywords for npm
Bugfix: REQ_OPTS not working for more args

REQ_OPTS was only replaced with "last" required argument
Make .help function more readable

Introduce opt variable to replace opts[optName]
Change skipEmpty check to make it read better (no more weird but working '' == [] check)
Refactor: Move parsing logic to seperate file

Rename parser.js to options-parser.js
Move .parse_ method to parser.js
Refactor: Move utility functions to helper.js
Refactor: main parsing engine

Split parsing into two separate responsibilities: parsing and semantics