Fix tests to work with new TagBlock parsing format.

- These are the fixes to the tests that could not be fixed by altering the core parsing code base.
- Most involve adding TagBlock's, breaking out existing markup blocks and altering some AcceptedCharacter formats.
- Was able to loosen the restrictions on AcceptedCharacter's to allow the body of html tags to accept any character.

#75

These test fixes are here due to the changes in this PR: https://github.com/aspnet/Razor/pull/86
odd to have separate tag _blocks_ for begin and end tags.  in this case, why doesn't the `MarkupBlock` just contain one (empty) `MarkupTagBlock`?