Implement rest
Use EMPTY-LIST when returning the rest of an empty seq
Implement second
Implement number type check boolean functions

  Introduce Protocols for Integer, Decimal & Float
Merge pull request #72 from patrickgombert/number-types

Implement number type check boolean functions
Merge pull request #71 from patrickgombert/rest

Implement rest
Implement byte, short, int & long
Merge pull request #73 from patrickgombert/number-cast

Implement byte, short, int & long