pkcs11-helper: update to 1.27

- fixes build with openssl 1.1
- add support for mbedtls as an option
- avoids regenerating autoconf bits

2020-11-17 - Version 1.27

* core: handle PIN expiration after C_Login as C_Login may take a while
* core: return explict success when plugin&play and no threading and no
  safefork, thanks to Tunnelblick

2020-01-21 - Version 1.26

* openssl: build with openssl ec disabled
* openssl: support RSA_NO_PADDING padding, thanks to Selva Nair
* core: reduce mutex lock scope of add/remove provider, thanks to Frank Morgner
* core: improve the fork fixup sequence

2018-08-16 - Version 1.25.1

* core: build with threading disabled

2018-08-04 - Version 1.25

* core: do not attempt to initialize provider with fork mode is not safe. Too
  many providers do not follow the PKCS#11 spec.

2018-06-15 - Version 1.24

* build: support libressl-2.7

2018-06-02 - Version 1.23

* build: cleanups.
* openssl: rework support 1.1.

2017-02-12 - Version 1.22

* spec: minor cleanups.

2017-01-06 - Version 1.21

* mbedtls: fix missing logic if issur certificate, thanks to Steffan Karger

2016-12-08 - Version 1.20

* polarssl: support polarssl-1.3, thanks to Steffan Karger.
* certificate: ignore certificate object without CKA_ID.
* openssl: fix memory leak, thanks to ASPj.
* openssl: support 1.1 and libressl, thanks to Daiki Ueno.

2013-10-11 - Version 1.11

* openssl: support generic pkey.
* openssl: add dsa support.
* openssl: add ecdsa support, thanks for Sanaullah for testing.

(nia)