Export more  functions from the Leemon Baird Big Integer library

I added the following static functions to the BigInt class:
- FromNumber: accepts only Number (no string representation)  and is faster than FromInt

I added the following methods to the BigInt class:
- divide: returns an array where the quotient is the first element and the remainder is the second
- subtract
- equalsNum: internally use the FromNumber function
- gcd: exports the eGCD LBaird library function

I changed the followings
- toRawBytes: previous implementation fails in some condition, reimplemented using a LBaird library function
- multiply: now works
- minor fixes