pkcs11-tool sets CKA_DECRYPT=true rather then CKA_DERIVE=true when generating EC keys (#277)

RSA and EC keys have different usage attributes. Appropriate attributes are set
When using --keypairgen the user can use the --usage-sign, --usage-decrypt,
and --usage-derive. to get finer control.

 Changes to be committed:
	modified:   tools/pkcs11-tool.c
PKCS#11 hashes for cards without RAW (see #241)

    The framework-pkcs15.c did not add hashes correctly if the card did not support RSA RAW.
    This change fixes that and only adds hashes if the card did not specify a list of hashes.
    It also will not add hashes done in software if ENABLE_OPENSSL is not specified.
    Some error conditions are also tested for EC mechanisms.

    See bug report #241 for more information.
IsoApplet: RSA key import - properly calculate the length of the entries