added missing wrappers
eac_ctx is not const in eac_ctx_init_ca
fixed CVC wrappers for non patched OpenSSL
fixed check for error
fixed memory leaks
simplifications in swig bindings

- use string2buf where possible
- take into account that OpenPACE does check inputs
use EAC_init() and EAC_cleanup()
fixed wrong free on error of CVC_d2i_CVC_CERT
added generic wrappers to OpenPACE's NIDs
added convenience wrappers for TA step 4-6
generic string wrapping for more languages

- string wrappers are now available in all languages that implement cstring.i
- fixes compilation for languages that don't implement cstring.i
- changes signature of PACE_STEP1_enc_nonce
added EAC_CTX_init_ef_cardsecurity
do CA key management only in CA_set_key

Previously EAC_CTX_init_ca created a new CA context and initialized it
with keys. So it was not possible to initialize an already given CA
context with keys.  Key initialization is now done in CA_set_key only.

- EVP_PKEY_set_keys takes over the functionality of EVP_PKEY_set_pubkey
- fixes bug from EVP_PKEY_set_keys when used with uninitialized DH key
- some cleanups in eactest
- some more error messages