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
Merge pull request #373 from sappo/master

updated documentation for zframe put/get api
changed api to get uints from frame, because 0 as error conflicts if one expects 0
updated documentation
Merge pull request #374 from sappo/master

Changed zframe uint API
Fixed issue #323

- also cleaned up zombie timer code on zloop; there was no need to
  allocate a block to store an integer, this could sit on the list
  item directly, with a suitable cast.

- minor cleanups to zframe.