why3: update from 0.83 to 0.85
libantlr3c: new derivation

libantlr3c is the C runtime library of ANTLR v3

Homepage: http://www.antlr3.org/
cvc4: new derivation

CVC4 is an efficient open-source automatic theorem prover for
satisfiability modulo theories (SMT) problems.

Homepage: http://cvc4.cs.nyu.edu/web/
oraclejdk: bump to 8u20

Closes #4492
the sha256 of cups 1.5.4 was that of a HTML (broken in md5->sha256 update)
thc-hydra: don't call this package "hydra"; that name is taken in NixOS