Use paths relative to the point of execution in doxygen rules.

This partly re-applies 5ae025b56a46a0046d7b0a6731e1bc04cc16188f with the
following changes:

- Use path-constant to deduce the path relative to the point of execution
  rather than the Jamfile.
- Use that path only to list source files to be passed to Doxygen.
- Keep the project rule, but remove the duplicate requirements that are
  explicitly specified in standalone_main.

Hopefully, this should work around the problem of Reference generation
in the official docs.

doc/Jamfile.v2

@@ -2,50 +2,19 @@
 # subject to the Boost Software License, Version 1.0. (See accompanying
 # file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
+import project ;
 import doxygen ;
 import quickbook ;
 
-project : requirements
-        # Path for links to Boost:
-        <xsl:param>boost.root=../../../..
-
-        # Some general style settings:
-        <xsl:param>table.footnote.number.format=1
-        <xsl:param>footnote.number.format=1
-
-        # HTML options first:
-        # Use graphics not text for navigation:
-        <xsl:param>navig.graphics=1
-        # PDF Options:
-        # TOC Generation: this is needed for FOP-0.9 and later:
-        <xsl:param>fop1.extensions=0
-        <xsl:param>xep.extensions=1
-        # TOC generation: this is needed for FOP 0.2, but must not be set to zero for FOP-0.9!
-        <xsl:param>fop.extensions=0
-        # No indent on body text:
-        <xsl:param>body.start.indent=0pt
-        # Margin size:
-        <xsl:param>page.margin.inner=0.5in
-        # Margin size:
-        <xsl:param>page.margin.outer=0.5in
-        # Paper type = A4
-        <xsl:param>paper.type=A4
-        # Yes, we want graphics for admonishments:
-        <xsl:param>admon.graphics=1
-        # Set this one for PDF generation *only*:
-        # default pnd graphics are awful in PDF form,
-        # better use SVG's instead:
-        <format>pdf:<xsl:param>admon.graphics.extension=".svg"
-        <format>pdf:<xsl:param>"admon.graphics.path=$(boost-images)/"
-        <format>pdf:<xsl:param>"boost.url.prefix=http://www.boost.org/doc/libs/release/libs/utility/doc/html"
-;
+project boost/libs/utility/doc ;
 
+path-constant INCLUDES : ../../.. ;
 path-constant boost-images : ../../../doc/src/images ;
 
 # Generate XML doxygen reference for base_from_member component in base_from_member_reference.xml
 doxygen base_from_member_reference
   :
-    ../../../boost/utility/base_from_member.hpp
+    $(INCLUDES)/boost/utility/base_from_member.hpp
   :
     <location>tmp
     <doxygen:param>ENABLE_PREPROCESSING=YES
@@ -89,7 +58,7 @@ doxygen base_from_member_reference
 # Generate XML doxygen reference for boost_binary component in boost_binary_reference.xml
 doxygen boost_binary_reference
   :
-    ../../../boost/utility/binary.hpp
+    $(INCLUDES)/boost/utility/binary.hpp
   :
     <location>tmp
     <doxygen:param>ENABLE_PREPROCESSING=YES
@@ -133,8 +102,8 @@ doxygen boost_binary_reference
 # Generate XML doxygen reference for call_traits component in call_traits_reference.xml
 doxygen call_traits_reference
   :
-    ../../../boost/call_traits.hpp
-    ../../../boost/detail/call_traits.hpp
+    $(INCLUDES)/boost/call_traits.hpp
+    $(INCLUDES)/boost/detail/call_traits.hpp
   :
     <location>tmp
     <doxygen:param>ENABLE_PREPROCESSING=YES
@@ -178,8 +147,8 @@ doxygen call_traits_reference
 # Generate XML doxygen reference for compressed_pair component in compressed_pair_reference.xml
 doxygen compressed_pair_reference
   :
-    ../../../boost/compressed_pair.hpp
-    ../../../boost/detail/compressed_pair.hpp
+    $(INCLUDES)/boost/compressed_pair.hpp
+    $(INCLUDES)/boost/detail/compressed_pair.hpp
   :
     <location>tmp
     <doxygen:param>ENABLE_PREPROCESSING=YES
@@ -223,8 +192,8 @@ doxygen compressed_pair_reference
 # Generate XML doxygen reference for in_place_factory component in in_place_factory_reference.xml
 doxygen in_place_factory_reference
   :
-    ../../../boost/utility/in_place_factory.hpp
-    ../../../boost/utility/typed_in_place_factory.hpp
+    $(INCLUDES)/boost/utility/in_place_factory.hpp
+    $(INCLUDES)/boost/utility/typed_in_place_factory.hpp
   :
     <location>tmp
     <doxygen:param>ENABLE_PREPROCESSING=YES
@@ -271,7 +240,7 @@ doxygen in_place_factory_reference
 # Generate XML doxygen reference for result_of component in result_of_reference.xml
 doxygen result_of_reference
   :
-    ../../../boost/utility/result_of.hpp
+    $(INCLUDES)/boost/utility/result_of.hpp
   :
     <location>tmp
     <doxygen:param>ENABLE_PREPROCESSING=YES
@@ -315,7 +284,7 @@ doxygen result_of_reference
 # Generate XML doxygen reference for string_view component in string_view_reference.xml
 doxygen string_view_reference
   :
-    ../../../boost/utility/string_view.hpp
+    $(INCLUDES)/boost/utility/string_view.hpp
   :
     <location>tmp
     <doxygen:param>ENABLE_PREPROCESSING=YES
@@ -359,7 +328,7 @@ doxygen string_view_reference
 # Generate XML doxygen reference for value_init component in value_init_reference.xml
 doxygen value_init_reference
   :
-    ../../../boost/utility/value_init.hpp
+    $(INCLUDES)/boost/utility/value_init.hpp
   :
     <location>tmp
     <doxygen:param>ENABLE_PREPROCESSING=YES
@@ -440,6 +409,5 @@ boostbook standalone_main
 alias boostdoc ;
 explicit boostdoc ;
 
-alias boostrelease :
-    standalone_main ;
+alias boostrelease : standalone_main ;
 explicit boostrelease ;