completed tests for dico

remove ForkInstance from list of checks
Merge remote-tracking branch 'upstream/master'
Add Check.That(null).IsAfter(...) fails to ensure 100% coverage

Adjusted namespace policy (to yes) for Helpers subfolder as only TimeUnit is within the root (NFluent) namespace
Added test fixture dedicated to edge cases and exploratory tests
Refactored IsEqualTo to include all types: value and classes

improved handling of null for IsEqualTo
Added tests for NotIsInstance on nullables
Added NotIsInstanceTests
Stylecop issues on generated T4
Added IsInstanceOf and IsNotInstanceOf for structs
Made Check.That(null).IsInstanceOf<T> alwais fail
Added small test for char
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/tpierrain/NFluent
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