int128 implementation

[fluffy]

Lets talk about much faster way to do the uint128 stuff.

On a bunch of stuff use, we can do it with direct compiler support for in128 and on others I would like to use a struct with two int64

[BrettRegnier]

This was something I was thinking about earlier, I don't think it will be very difficult to get this to work with some bitwise magic with the value itself. When we can we can setup a meeting to get this discussed! :)

[BrettRegnier]

One of the ideas I was thinking of was a vector of uint64_t elements and the big_uint is initialized with x amount of bits it will calculate how many elements it requires and keeps track of the number of bits it uses.

[BrettRegnier]

This has been overhauled in this commit