Reorganized the DH APIs into groups.
Reworked all DH APIs.
Improved testing of DH API.
Implemented wolfSSL_PEM_read_RSAPublicKey() and
wolfSSL_PEM_write_RSA_PUBKEY().
Fix public key PEM write implementations to use the correct
header/footer names.
Added support for "RSA PUBLIC KEY" in header and footer in DerToPemEx().
Reworked PEM read/write APIs to be independent. No longer create an EVP
to use common function - common functionality refectored out.
Similarly file APIs don't create a BIO and call the partner APIs.
Improved testing of PEM read/write APIs.
Generic read BIO from memory BIO now returns the buffer instead of
allocating memory and reading.
No longer reading chunks when a file BIO.
Added wolfssl_make_rng() to create or get get global random. All RSA and
DH APIs now use this. DH_generate_parameters() creates a random object
and use global on error rather than just using global random.
Changed implementations to use BIO_new_fp() instead of create a new BIO
and setting file pointer.
dad62fc182