We've been using int for the size for a long time, it's about time...
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>

We use the sysconf function to provide details about the page size in the
secure memory code. This function can return -1 on error so we should check
for this before proceeding.
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Reviewed-by: NKurt Roeckx <kurt@openssl.org>

-Wincompatible-pointer-types-discards-qualifiers (the latter did not require
any code changes).
Reviewed-by: NRich Salz <rsalz@openssl.org>

There are many places (nearly 50) where we malloc and then memset.
Add an OPENSSL_zalloc routine to encapsulate that.
(Missed one conversion; thanks Richard)
Also fixes GH328
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRich Salz <rsalz@openssl.org>

Move #include's inside the #ifdef.
Reviewed-by: NMatt Caswell <matt@openssl.org>

Add secure heap for storage of private keys (when possible).
Add BIO_s_secmem(), CBIGNUM, etc.
Add BIO_CTX_secure_new so all BIGNUM's in the context are secure.
Contributed by Akamai Technologies under the Corporate CLA.
Reviewed-by: NRichard Levitte <levitte@openssl.org>