Web: import new web site from web-gop branch.
Overall structure by Graham, with many comments and suggestions from
-user. Patrick McCarty worked extensively on the css and its
integration with texinfo. Jonathan worked on the Introduction.
Patrick Schmidt did further work on the CSS and the News page.
I reworked the structure of files and directories to integrate it as
well as possible in Lily sources structure and build system.
Status/to-do of this draft:
* no PDF output -- best would be to generate per-page PDF and add
"Print this page" links from HTML pages, which will be doable with a
Texinfo parser;
* no big HTML page output: this makes little sense for a website, and
the init file is currently not compatible with it: the images paths
in the CSS would need to be adjusted to have both one big page and
multiple pages outputs;
* HTML output: file names should be tweaked, which requires converting
Jan's patch to texi2html script into a function in
web-texi2html.init;
* SVG annotated images should be converted to PNG;
* examples of LilyPond scores are missing, they will likely go into a
new directory e.g. Documentation/examples;
* top news in the HTML website and a RSS feed should be generated from
Documentation/general/news.itexi;
* cross-references mechanisms between the new web site and the manuals
should be set up;
* download links should be generated using update-version database;
* online and offline targets should be adjusted;
* support for translating this document is yet to be added;
* the CG should be updated.