- Move all of the ec functions into the Common::ec namespace.
- Give the public functions better names and some usage information.
- Move all of the "elt" related functions into an "elt" class including
all of the arithmetic operations, so that the logic becomes clearer
and feels less like assembly.
This also makes it much more obvious what the parameters are, instead
of only using unsigned char* (which doesn't tell anything about what
the pointer is used for or the size).
- Similarly, add a new "Point" class and move point functions there.
Overload the arithmetic operators to make calculations easier to read
