Added BuildRichTextAppearanceStreams property in GcPdfDcoument class to generate appearance stream for free text and line annotations with rich text content.
Added AnnotationBase.RemoveAppearance method to remove all appearance streams assiciated with the current annotation.
Added support for new class GcHTMLBrowser for converting HTML markup to PDF.
Added other supporting classes such as BrowserFetcher, HtmlPage, LaunchOptions, PageOptions, TimeoutOptions.
Added another class, GcPdfGraphicsExt is added to provide extension methods for rendering HTML to GcPdfGraphics.
Added appearance streams for all the annotation types except for rich texts in free text and line annotations.
Replace custom-built Chromium with Chrome or Edge which is installed in OS, or you can now download chromium from a public website as well.
