added Array.prototype.compact() method...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
fixed a typo...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>
some tweaks + moved to Array.prototype.compact()...

Signed-off-by: Alex A. Naanou <alex.nanou@gmail.com>