Added missing docblocks.
Removed TODO comment.

Using a function like in_array() or array_search() would be more cumbersome and inefficient because the way it is now we can break the cycle whenever we find a match and return the index if need be.
Added basic numeric operations to the num class.
Fixed some misspelled test function names.
Changed the mod() function to return float and use fmod() function instead of the modulus operator % which only works as intended for integers (the result is casted into an integer).
Added type specific basic numeric operations.
Specify a warning in the class docblock about strict-typed functions for numeric classes.
Fixed license inline docblock tag.
Removed an unneeded warning due to recent class docblock changes.
Fixed inline docblock tags.
Fixed missing docblock information.
Formatted code.