Add support for parsing RTF email messages #16
Description
As disscussed in #15 there are Outlook msg files that have only RTF body, which were created from RTF directly, not from HTML (you can create such email in Outlook by selecting FORMAT TEXT tab -> Format section -> Rich Text when creating a new message). Current parser doesn't parse such emails even closely to something readable.
To support this we need a generic RTF parser, which can parse generic RTF file and then convert it to HTML. It should handle handle all RTF formatting like \pard\plain \f0\b and convert it to HTML tags (like <div>, <span>, etc.) and style attributes (like font-size, font-family, etc.)
Probably we can combine current parser and generic one written by kschroeer/rtf-html-java.