Signed-off-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Add CRYPTO_EX_DATA add EndC_KEY_[gs]et_method, From Roumen Petrov.
Had to add various exdata calls to init/copy/free the exdata.
Had to remove const from some EC functions because exdata isn't
const-correct. :(
Also remove EC_EXTRA_DATA and use a union to hold the possible
pre-computed values and an enum to tell which value is in the
union. (Rich Salz)
Reviewed-by: NDr. Stephen Henson <steve@openssl.org>

Add CRYPTO_free_ex_index (for shared libraries)
Unify and complete the documentation for all "ex_data" API's and objects.
Replace xxx_get_ex_new_index functions with a macro.
Added an exdata test.
Renamed the ex_data internal datatypes.
Reviewed-by: NMatt Caswell <matt@openssl.org>