ECC doc update

[karel-m]

Add doc for changes introduced in 24c0eb8

• new ecc_get_curve(const char* name_or_oid, const ltc_ecc_curve** cu)
• new ecc_set_dp(const ltc_ecc_curve *cu, ecc_key *key)
• new ecc_generate_key(prng_state *prng, int wprng, ecc_key *key)
• new ecc_set_key(const unsigned char *in, unsigned long inlen, int type, ecc_key *key)
• new ecc_get_key(unsigned char *out, unsigned long *outlen, int type, const ecc_key *key)
• new ecc_get_oid_str(char *out, unsigned long *outlen, const ecc_key *key)
• obsolete: ltc_ecc_set_type (replaced by ltc_ecc_curve)

From the last part of ECC changes:

• new ecc_export_openssl
• new ecc_import_openssl
• new ecc_import_x509

It will take some time.

[sjaeckel]

I allowed myself to kill your travis build as it only changes docs that aren't built anyways :)

Btw. I think [skip ci] is useful in cases like that

[karel-m]

@sjaeckel ping

It would be nice to have the doc updated as there are questions related to the new ecc API e.g. #419

[sjaeckel]

I think I'm done with it.

Feel free to have another look over it and/or merge please :)

[sjaeckel]

Ah, I forgot that I've added some comments/questions, can you please comment on them before merging?

[karel-m]

Ad ecc_set_curve instead of ecc_set_dp - I am for renaming. I'll update the doc to use ecc_set_curve and create a separate PR with the actual renaming.

Ad ecc_make_key_ex I'll move it to Legacy Key Generation

[karel-m]

@sjaeckel please have a look at the last two commits

[sjaeckel]

👍

please merge after #423