Problem: inconsistent naming style for private data members, conflicts with naming of local variables and member functions

Solution: apply and check _lower_case naming style for private data members

Solution: remove else

Solution: define and apply parameter naming style: lower_case_

Solution: replace by C++-style casts

Problem: missing tests for zmq_timers_* corner cases, missing handling of such corner cases, code duplication, missing assertions in test code

Solution: add tests, add checks to timers_t, add match_by_id functor, add assertions

Solution: Phase I - make precompiled.hpp be first file included in every source file

Solution: fixed project files, and warning in timers.cpp

Solution: update to 2016