Implement the 'boost:' for links relative to boost root. Also, optionally

replace links within the boost distribution with links to the the boost site,
which is useful for generating pdfs and standalone documentation.

Implemented with John Maddock. Fixes #1166.

[SVN r51261]

doc/test/Jamfile.v2

@@ -164,6 +164,7 @@ boostbook standalone
         # PDF Options:
         #======================================================================
         <format>pdf:<xsl:param>img.src.path=$(images_location)/
+        <xsl:param>boost.url.prefix=http://www.boost.org/doc/libs/release/doc/test/html
     ;
 
 

doc/test/test.qbk

@@ -375,6 +375,15 @@ The code should be syntax highlighted.
 Try this: [@http://www.boost.org this is [*boost's] website....] it should
 be visible as a link.
 
+This is [@../../../boost/math/distributions.hpp a link to a header file (boost/math/distributions.hpp)],
+it should be rewritable and point to the website when built as a PDF.
+
+This is [@boost:libs/regex/index.html a link to another library's documentation (Boost.Regex)], using the boost: protocol,
+it should be rewritten to point to the website when building a PDF.
+
+This is [@boost:/libs/regex/index.html a link to another library's documentation (Boost.Regex)], using the boost:/ protocol,
+it should be rewritten to point to the website when building a PDF.
+
 [endsect]
 
 [section Footnotes]

tools/boostbook

@@ -1 +1 @@
-Subproject commit 82858e99f6c0d4399e93f7b8ba8f019ced599e07
+Subproject commit 2423ae5950004025de315ca46f7acc51c91ea366