Document -debug_decrypt option.
(cherry picked from commit 0dd5b94aeb77c2982bdf6886962b7a8491c6c9ed)
Fix double frees.
Fix use after free.
Add new sponsors
(cherry picked from commit 351f0a124bffaa94d2a8abdec2e7dde5ae9c457d)
Fix eckey_priv_encode()

Fix eckey_priv_encode to return an error on failure of i2d_ECPrivateKey.
Fix version documentation.

Specify -f is for compilation flags. Add -d to synopsis section.

(cherry picked from commit 006397ea62bbcae22c8664d53c2222b808c4bdd1)

Closes #79.