Add an AEAD EVP interface to libcrypto, along with AES-GCM AEAD
implementations. This largely pulls in Adam Langley's AEAD patches from
Chromium's OpenSSL.

ok miod@
KNF.
KNF.
KNF.
Add a ChaCha20-Poly1305 AEAD EVP implementation to libcrypto, from Adam
Langley's Chromium OpenSSL patches.

ok miod@
KNF.
Use C99 initialisers for the AEAD struct.
More KNF.
No longer make pqueue.h a public (and installed) header file. Replace its
inclusion in <ssl/dtls1.h> by the benign
`struct _pqueue; typedef struct _pqueue *pqueue;'.

Note that said dtls1.h should probably be considered a private header as well...

ok beck@
Replace ASN1_GENERALIZEDTIME_adj(), ASN1_UTCTIME_adj() and
ASN1_TIME_to_generalizedtime() with wrappers around their former
implementations, making sure memory allocated is freed in all failure cases.

help and ok from beck@ and Brendan MacDonell.
Fix memory leaks upon failure.
ok beck@
When OPENSSL_LOAD_CONF was added it ended up with more #if 0 code,
more #ifdefs and a new source file that contains a single function.

Nuke the #if 0 code that is now a macro and move the single function in
evp_acnf.c to c_all.c, which is where the other code lives. While here,
tidy evp.h slightly, remove an unnecessary #ifdef __OpenBSD__ and nuke
a comment that is now a lie.

ok miod@
switch RSA key generation default to 2048 bits (matching ssh); ok miod@
deleted seed some time ago
deleted seed some time ago
no no seed
no no md2
no no md2
simple reallocarray to check multiplies. ok guenther
add missing header needed for mem{cpy,cmp}()

ok tedu@