Increment version to 4.0.0, update NEWS and README

NEWS

@@ -1,3 +1,10 @@
+* Version 4.0.0 (not yet released)
+ ** Major release: Changed backend from M2Crypto to cryptography
+ ** Added: dependency on cryptography 1.0 or higher
+ ** Removed: dependency on PyASN and PyASN-modules
+ ** For now M2Crypto is still needed for verifying issuer certificates
+ ** utils.rand_bytes() now sources bytes from os.urandom()
+
 * Version 3.2.0 (released 2015-06-16)
  ** License change release: Changed license to BSD 2-clause.
 

README

@@ -6,10 +6,15 @@ To read more about U2F and how to use a U2F library, visit
 link:http://developers.yubico.com/U2F[developers.yubico.com/U2F].
 
 === Dependencies
-u2flib-server depends on M2Crypto. On a Ubuntu system, this can be installed with
+u2flib-server depends on link:https://pypi.python.org/pypi/cryptography[cryptography],
+which requires libffi, OpenSSL, and a C compiler to build.
+On a Debian or Ubuntu system, the build dependencies can be installed with
 the following command: 
 
-  $ apt-get install python-m2crypto
+  $ sudo apt-get install build-essential libssl-dev libffi-dev python-dev
+
+For Windows the cryptography project provides prebuilt wheels.
+For other platforms refer to link:https://cryptography.io/en/stable/installation/[cryptography installation].
 
 === Installation
 u2flib-server is installable by running the following command:

u2flib_server/__init__.py

@@ -25,4 +25,4 @@
 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
-__version__ = "3.2.1-dev"
+__version__ = "4.0.0-dev"