Merge branch 'refs/heads/t/rm_asn'

A few cleanups, and one patch which removes an obsolete feature,
getting rid of an open-coded ASN parser.

Cooking for three months.

* refs/heads/t/rm_asn:
  Remove unused E_PUBLIC_KEY.
  crypt.c: Combine load_key() and get_private_key().
  crypto: Remove support for ASN public keys.
  crypto: Simplify asymetric key handling.
  crypto: Rename check_key_file() -> check_private_key_file().
  gcrypt.c: Always initialize result pointer in get_private_key().

diff --cc NEWS.md
index d441db42d13aaeed62942369acef56a2fdffacae,d9326db76cfa80b50a8a268fef1b29f966cdeb09..771e12df19c0a72efe530b5d880ab375404d44e6
--- 1/NEWS.md
--- 2/NEWS.md
+++ b/NEWS.md
@@@ -1,16 -1,6 +1,20 @@@
  NEWS
  ====
  
 +------------------------------------
 +0.6.0 (to be announced) "fuzzy flux"
 +------------------------------------
 +- Support for Mac OS X has been removed.
 +- On Linux systems, glibc-2.17 or newer is required to build the
 +  source tree.
++- Support for RSA public keys in ASN format (as generated by openssl
++  genrsa) has been removed. These keys have been deprecated since
++  2011, so users should have long switched to keys generated with
++  ssh-keygen(1).
 +
 +Downloads:
 +[tarball](./releases/paraslash-git.tar.bz2),
 +
  -------------------------------------
  0.5.7 (2016-12-31) "semantic density"
  -------------------------------------

diff --cc error.h
Simple merge