Set up Coverity (static code analysis)

[sowle]

Set up Coverity and incorporate it in CI scheme.

A note Regarding double try-catch.
They seem to be useless in our case because we're using C++11
In C++11 another exception cannot be thrown if there's already one in-flight, it will trigger std::terminate immediately. What's to do:

1. Implement custom std::terminate handler to catch and log such issues (at least we will be aware that smth went wrong) -- done
2. Consider adding to the code standard using noexcept(false) in destructors.
3. Make all logging routines and mactors excepton-safe.
4. Make sure all this stuff passes Covetity
5. Refactor CATCH_* macros

[cryptozoidberg]

Coverity Scan integration is setup: https://scan.coverity.com/projects/zanoproject
TODO: add automation

[cryptozoidberg]

First iteration of fixes finished, new iteration planed with #149