MOD: modified DE solver to take an instance of a learning method object as an argument
MOD: modified all examples and unit-tests to reflect the adjustments

FIX: 'ubuntu_boost_system' was incorrectly compiling a local copy of boost which made this continuous integration test pointless

FIX: 'ubuntu_boost_system' was incorrectly compiling a local copy of boost which made this continuous integration test pointless

FIX: fixed an issue with ExprtkWrapper being incorrectly destryed before being used in the NetworkSum class

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MOD: Modified examples and unit tests to account for the changes