renamed method '_count' to '_size' as rfc 21 dictates
fix zeromq/czmq#609 : Changed zloop timer to use fixed interval from start of loop instead of current time plus interval
Merge pull request #612 from sappo/master

Renamed zinterface method '_count' to '_size' as rfc:21 dictates
Merge pull request #613 from poljvd/master

fix zeromq/czmq#609
Merge pull request #614 from hintjens/master

Problem: zdlist isn't very communicative
Deprecated zlist_head/tail as useless

I've not seen any code using these, so am deprecating them. If you
feel strongly about this, feel free to revert this commit.