* use requiredInit
Use requiredInit on keys - this simplifies error handling by providing
more compile-time guarantees through type.
Loophole: `clear` will leave an invalid key type in memory, not
guaranteed by type - it requires an explicit action to produce, so it's
somewhat better than the current situation where by default, keys are
invalid, but it's not watertight.
something like a `sink` would be needed which would have to guarantee
that `clear` is the last use of the instance.
* close requiresinit loophole
* remove clear for public stuff
* fix side effects
`secp256k1_context_no_precomp` is constant actually
* document nosideeffect
* document nosideeffect
* document fix
Jacek Sieka
cheatfate
cheatfate
Yuriy Glukhov
Zahary Karadjov