simplified some of the DynamicPublishedContent methods to accept Func<IPublishedContent> instead of Func<DynamicPublishedContent>, made the IsHelper method private as this shouldn't be exposed.
renamed other objects starting with DynamicDocument to DynamicPublishedContent
an UmbracoHelper property to the PluginController class which will expose any methods needed by devs to retreive media or content.
Have updated UmbracoHelper with loads of new helpful methods and moved the Wrap methods to HtmlHelper extensions because this is purely to
do with rendering html (have written unit tests for it too).
Updated some 'library' methods to proxy calls to UmbracoHelper so we only have to maintain one set of code.
Added a convenience property to UmbracoContext to return the current NiceUrlProvider so you don't have to go through the RoutingContext to get it.
all calles in RazorLibraryCore for Wrap to UmbracoHelper. Fixed up the HtmlTagWrapper classes so they have immutable properties and replaced
public fields with Properties.
the methods in UmbracoHelper so we only have to maintain one set of code. Didn't port over the Wrap methods because
I need feedback on these as to what they do/are supposed to do.
Added the Media methods to UmbracoHelper using the media store stuff.
