Add doc generation infrastructure to the translations
of the server guides. These currently include Intro,
P4Dist, P4Guide, and P4SAG (the 2014.1 versions).
This change includes:
- adding a lang attribute to each guide to specify
either "ko_kr" or "zh_cn" as appropriate, to inform
DocBook transformations which generated elements
(including TOC, chapter headings, cross-reference
link text) to use.
- Included the English screenshots for Intro and
P4Guide, since these were not translated.
- Tweaked the way common XML files are included
to not depend on relative path structure (since the
translations are nested within the English guide
directory).
- The common XML files have not yet been translated,
so PDF or HTML transformations still include English
content. Also, the HTML presentation includes English
for various items, such as the search pane; these too
have not yet been translated.