Release 1.03.65.html5-css.222

Development release of the HTML 5 branch, which allows layout using different styles using CSS.

• New html5 transformation uses different CSS styles to control rendering.
• CSS styles can be controlled by adding different variants on top of the main style - RISC OS 2 style, or with different fonts, etc.

Changes since 1.03.65.html5-css.179:

• compatibility/version-table/version elements have been added.
• strong and em are better supported, and should be differentiated with Fraunces font.
• alternates element allows alternative parameters which are not optional (similar to <optional alternates=true>)
• Offset table alignments are now left, and a CSS variant allows them to align right.
• image elements are more reliable and can be positioned horizontally; gif format explicitly supported.
• html transform now supplies the title properly (previously might omit the title in indexed documents).
• Indexed generation now supports front-matter, and automatic cover page generation.
• Front-matter pages are styled for title, dedication, copyright and epigraph.
• reference elements which supply explicit text no longer implicitly prefix with the reference type prefix.