Feature/is session active#33

[OGKevin]

Context

#33

What has been done

This pr introduces a new way to handle SessionContext. Now it is possible to do the following:

if (!apiContext.IsSessionActive()) {
    apiContext.ResetSession();
    apiContext.Save();
}

This way there is no saving an unchanged context.

Closes #33

[dnl-blkv]

Looks good!

[dnl-blkv]

@andrederoos