This is the first step to supporting dynamic reservations. The goal of this task is to enable a framework to reply to a resource offer with Reserve and Unreserve offer operations as defined by Offer::Operation in mesos.proto.
It's divided into a few subtasks so that it's clear what the small chunks to be addressed are. In summary, we need to introduce the Resource::ReservationInfo protobuf message to encapsulate the reservation information, enable the C++ Resources class to handle it then enable the master to handle reservation operations.
- The framework will be able to send back reservation operations to (un)reserve resources.
- The reservations are kept only in the master since we don't send the CheckpointResources message to checkpoint the reservations on the slave yet.
- The reservations are considered to be reserved for the framework's role.