Added a Linux b2 build without OpenSSL
Fixed issue in install_boost.py that made rebuilds to error
Removed workaround for https://github.com/boostorg/boost/issues/711
Changed boost.mysql.use-ts-executor default value to off
close#235
Fully migrated Linux and Windows jobs to Drone
Fixed time-zone related issue in integ tests
Support for MSVC 14.1
Support for latest docca version
Recover codecov support
Test to verify cmake find_package for a b2-generated distribution
Resilience against openssl not being found in Windows