Harmonized behaviour when point length is invalid.
Some small performance improvements on 32-bit architectures.
Some more renaming to avoid shadowing.
Some renaming to avoid spurious warnings on some old GCC versions.
Fixed modular reduction bug in the special field for P-256 (in some rare cases, value would end up being negative, which would corrupt subsequent operations).
Added optimised implementation of P-256 that uses 32->64 multiplications (MUL31).