Link in libuuid
Fixed #322
Additional files for issue #322
Fixed #325

- zcert_new returns NULL when libsodium isn't installed
zproxy did not build with pre-4.x versions of ZeroMQ

- for versions prior to 3.2.1, use zmq_device instead of zmq_proxy
- does not implement capture socket on these older versions
zproxy fix for older versions was not working

- selftest did not work properly with zmq_device as underlying engine
- conditional compile was using wrong macros
Merge pull request #324 from hintjens/master

Fixed #322
Fix #326

`sys/param.h` is already conditionally included in `czmq_prelude.h`.

Signed-off-by: Shannen Saez <shannenlaptop@gmail.com>
Merge pull request #328 from shancat/sha1_windows

Fix #326
Add missing #defines for Android.

`S_IREAD` & `S_IWRITE` are deprecated.

Signed-off-by: Shannen Saez <shannenlaptop@gmail.com>
Merge pull request #327 from shancat/master

Add missing #defines for Android.