Create a new big number.

Prototype
   bnum BigNum.new( num )

Parameters
   num
      String or Big Number or Float or nil.

Remarks
   If num is a String or a Big Number, bnum is a representation of num.
   If num is a Float, bnum is a representation of the integer part of num.
   If num is nil, bnum is a representation of number zero.

Example
   
require( "BigNum.lua" )

a = BigNum.new( "298370" )
b = BigNum.new( a )
c = BigNum.new( )

print( a )
print( b )
print( c )
   

Output
   
298370
298370
0