#3 Presage crashes if config file is missing due to ONLINE_LEARNING not being in the default profile

[Michael Sheldon]

Currently if you try to start a libpresage application and it can't find the presage.xml configuration file it will exit with the following error:

terminate called after throwing an instance of 'Configuration::ConfigurationException'
what(): [Configuration] Cannot find variable Presage.ContextTracker.ONLINE_LEARNING

This is because the ONLINE_LEARNING setting isn't present in the default profile which gets loaded when no configuration file is available.

The attached patch adds this setting to the default profile