SSL.Constants: Minor documentation change.
Nettle.BlockCipher: make sure block_size is positive
Standards.JSON: keep the validation flag in a local variable
Standards.JSON: fix a ragel file

Commit 623497f223629c11556479c1f49b665a96a7e136 changed json_parser.c
and json_parser.rl inconsistently. I assume the compiled one was
actually tested, so this commit makes sure the .rl file compile into
the same code as before this commit.
Standards.JSON: fix -Wuninitialized warnings

GCC complains about the variables m and a to be used uninitialized.
This is not correct, so we silence the warning.