Updates the web site home page.
Merge branch 'master' of https://github.com/dupdob/NFluent
Fixes the unit test that was failing after the pull from @Cyrdup

Now, IsInstanceOf<T>() fails with null values, but not with null values of the same nullable type than T
Small refactor so that the IInstanceHelper code relies on the existing ExtensionsCommonHelpers.IsNullable() extension method.
Adds a unit tests showing that IsEqualTo() works with a nullable DateTime.
Updates the home page.
Updates the home page
Turns the home page button into yellow.
Fixes few stuffs within the home page.
Improves the display of the home page.
Improves the home page.
Added IsNegative for number types