Opaque

One tiny new feature is the unlink_masking_key mechanism, which ensures that all user records belong to the same threshold-setup are unique, and thus unlinkable. however the usage of 3hashTDH negates this, as the zero record makes them trivially linkable, by testing which zero record shares reconstruct to zero. So either you have 3hashTDH or you have unlinkable user records. can't have both. maybe, for now.

anyway. yay for v1.0 \o/

this release comes with a few fixes, and the 3hashTDH primitive for the threshold variant, it also dispenses with the previous approach of using a proxy for doing threshold oprfs, which made little sense.

minor cosmetic changes, and some fixes to make packaging go more smoothly. biggest change is the addition of `opaque_CreateRegistrationResponse_extKeygen() ` which is part of the upcoming new threshold OPAQUE interface.

small fixes, mostly in the makefile and thing related to building the binary library.

this fixes a small discrepancy between the c client and the java bindings. thanks to krispypen
no other changes.