Update zsys.c

the self test forgets to delete the folder ".testsys"
(correct me if I'm wrong)
On my machine, this adjustment fixes the problem.
Merge pull request #364 from MilfordTea/master

Update zsys.c
Fixed issue #366
Whitespace & formatting fixes
Fixed a comment
Debugging CI build errors
Updating man pages
Use bogus hostname if getnameinfo fails
Fixed issue #370
Fixed #370 in zmsg, zcert, zcertstore, zauth
Removed dependency on ZMQv4 proxy functions

- re-implemented proxy logic in zproxy background task
- added optimization for polling costs, by looping on all messages
  coming from a socket, before returning to polling. This makes a
  significant difference on OS/X especially.
- removed checks for zmq_proxy_steerable from configure.ac
Merge pull request #367 from hintjens/master

Fixed issue #366
put/get 8,16,32,64 bit numbers, and string in network byte order to a single frame
Merge branch 'master' of github.com:zeromq/czmq
Merge pull request #371 from sappo/master

 put/get 8,16,32,64 bit numbers, and string in network byte order to a single frame
Small improvements to zframe_put/get integers

- return -1 on error, not 1
- unrolled loops are simpler and faster
- slightly tweaked API methods
- modified methods so error handling is last
- don't assert on invalid frames (frames are external data)
Merge pull request #372 from hintjens/master

Small improvements to zframe_put/get integers
updated documentation for zframe put/get api
add a block of data to a frame
updated zframe block description