Adding eager null checking to Lazily.map.
Adding eager null checking to Lazily.each.
Adding eager null checking to Lazily.rest.
Adding eager null checking to Lazily.batch.
Adding eager null checking to Lazily.index.
Adding eager null checking to Lazily.slice.
Adding eager null checking to Lazily.equate.
Adding eager null checking to Lazily.take* and Lazily.drop*.
Adding eager null checking to Lazily.cycle and Lazily.repeat.
Adding eager null checking to Lazily.zip variants and Lazily.enumerable.
Adding eager null checking to Lazily.comprehension.
Adding eager null checking to Lazily.cartesianProduct.
Adding eager null checking to Lazily.filter Lazily.reject and Lazily.partition.
Merge pull request #172 from tobyclemson/null-checks

Adding eager null checks to all methods in Lazily.