Added the "arguments" type

The detection is based on Object.prototype.toString, exactly as for the arrays.
Also, it is the first half of #6.
Added the "primitive" type

The detection is based on wether the value is an complex objet or not.
Some unit tests have been added, and the #check function has been fixed to accept types that might match null and undefined.
Also, it finally fixed #6.
Release v0.1.1

 - Improved internal process
 - Improved module export
 - Added the "arguments" type
 - Added the "primitive" type