string: memstring functions
string: locale-independent float handling
string: explicit_bzero
msvc: fail on non-x86, instead miscompiling
endian: WORDS_UNALIGNED_ACCESS_OK (draft)

Seems it might be useful (mainly inside endian.h) for non-gcc/clang
compilers, but needs proof.
hashing: memhash

Fast in-memory hash, with randomized value.
win32 cleanups
pthread: non-working once wrapper
csrandom, keccak_prng, chacha: new modules

csrandom implements arc4random_buf api.

keccak_prng implements PRNG based on Keccak sponge.

chacha implements ChaCha hash.
chacha: make faster
string: use memset_s for explicit_bzero
regex: simplify op_count_full error check

There was dummy loop with size limit for "performace" reasons,
but it triggered automatic checkers.  Remove complexity
by using strchr() there.

Reported-By: David Binderman