Initial commit.
Project structure after yandex-contest-invoker split.
CMakeLists.txt minor style fix.
detail::execution::async_process_group_detail::DescriptorMonitor bug fix.
AsyncProcessGroupMultiple test set minor style fix.
CLI: Process::ResourceLimits::hardMemoryLimitBytes support.
Exceptions virtual inheritance bug fix.
detail::execution::AsyncProcessGroup implementation based on cgroup (draft).
detail::execution::async_process_group_detail::ProcessGroupStarter::terminate() bug fix.
detail::execution::async_process_group_detail::ProcessStarter::startChild() bug fix.
detail::execution::ProcessGroupStarter improvements.

Each control group is removed after process termination.
This behavior is validated in destructor.
Process::ResourceLimits::hardMemoryLimitBytes field was removed.
detail::execution::ProcessStarter::startChild(): excess throw command was removed.
detail::execution::async_process_group_detail::ProcessStarter::setUpControlGroup() cgroup configuration.

*) memory oom settings
*) cpuset and memory migrate settings
detail::execution::async_process_group_detail::ProcessStarter::startChild() fix.

Attach task to cgroup just before dropId() call.
filesystem::FIFO implementation.
filesystem fix: <boost/serialization/export.hpp> include was removed.
CMakeLists.txt: add_binary_targets() integration.
detail::execution::async_process_group_detail::Pipe::End::Type became INCLASS_STREAM_ENUM.
filesystem::DeviceType became filesystem::Device::Type INCLASS_STREAM_ENUM.