Fix NULL-return checks in 1.0.2

RT4386: Add sanity checks for BN_new()
RT4384: Missing Sanity Checks for RSA_new_method()
RT4384: Missing Sanity Check plus potential NULL pointer deref
RT4382: Missing Sanity Check(s) for BUF_strdup()
RT4380: Missing Sanity Checks for EVP_PKEY_new()
RT4377: Prevent potential NULL pointer dereference
RT4375: Missing sanity checks for OPENSSL_malloc()
RT4374: Potential for NULL pointer dereferences
RT4371: Missing Sanity Check for malloc()
RT4370: Potential for NULL pointer dereferences

Also expand tabs, make update, typo fix (rsalz)
Minor tweak by Paul Dale.
Some minor internal review feedback.

Reviewed-by: Richard Levitte <levitte@openssl.org>