Merge fixes from Trunk - mainly warning suppression.

[SVN r65720]

doc/install.qbk

@@ -34,34 +34,64 @@ please refer to the
 
 [h4 Building With Unicode and ICU Support]
 
-A default build of this library does not enable Unciode support via ICU.  
-There is no need to enable this support if you don't need it, but if you 
-use ICU for your Unicode support already, and want to work with 
-Unicode-aware regular expressions then read on.
+Boost.Regex is now capable of performing a configuration check
+to test whether ICU is already installed in your compiler's
+search paths.  When you build you should see a message like
+this:
 
-Most of the information you will need is in the getting started guide, 
-the only additional step you need to take is to tell bjam that you want 
-Boost.Regex to use ICU and optionally to tell bjam where ICU is located.
+   Performing configuration checks
 
-If you're building on a Unix-like platform, and ICU is already installed in 
-your compilers search path (with an install prefix of `/usr` or 
-`/usr/local` for example), then set the environment variable `HAVE_ICU` to 
-enable ICU support.  For example you might build with the command line:
+       - has_icu builds           : yes
 
-[pre bjam -sHAVE_ICU=1 --toolset=toolset-name install]
+Whick means that ICU has been found, and support for it will be enabled
+in the library build.  
 
-If ICU is not already in your compiler's path then you need to set the 
-environment variable `ICU_PATH` to point to the root directory of your 
-ICU installation, for example if ICU was installed to `/usr/local/icu/3.3` you 
+[tip If you don't want the regex library to use ICU then build with the 
+"--disable-icu" command line option.]
+
+If instead you see:
+
+   Performing configuration checks
+
+       - has_icu builds           : no
+
+Then ICU was not found and support for it will not be compiled into the library.
+If you think that it should have been found, then you will need to take a look
+at the contents of the file ['boost-root/bin.v2/config.log] for the actual error
+messages obtained when the build carried out the configuration check.  You will
+then need to fix these errors by ensuring your compiler gets invoked with the correct
+options, for example:
+
+[pre bjam include=some-include-path --toolset=toolset-name install]
+
+will add "some-include-path" to your compilers header include path, or if ICU
+has been built with non-standard names for it's binaries, then:
+
+[pre bjam -sICU_LINK="linker-options-for-icu" --toolset=toolset-name install]
+
+Will use ['"linker-options-for-icu"] when linking the library rather than the default
+ICU binary names.
+
+You might also need to use the options "cxxflags=-option" and "linkflags=-option" to set compiler and linker
+specific options.
+
+[important Configuration results are cached - if you try rebuilding with different compiler
+options then add an "-a" to the bjam command line to force all targets to be rebuilt.]
+
+If ICU is not already in your compiler's path, but instead headers, libraries and binaries
+are located at ['path-to-icu/include], ['path-to-icu/lib] and ['path-to-icu/bin] respectively
+then you need to set the environment variable `ICU_PATH` to point to the root directory of your 
+ICU installation: this typically happens if you're building with MSVC. 
+For example if ICU was installed to `c:\download\icu` you 
 might use:
 
-[pre bjam -sICU_PATH=/usr/local/icu/3.3 --toolset=toolset-name install]
+[pre bjam -sICU_PATH=c:\download\icu --toolset=toolset-name install]
 
-Note that ICU is a C++ library just like Boost is, as such your copy of 
+[important ICU is a C++ library just like Boost is, as such your copy of 
 ICU must have been built with the same C++ compiler (and compiler version) 
 that you are using to build Boost.  Boost.Regex will not work correctly unless 
 you ensure that this is the case: it is up to you to ensure that the version 
-of ICU you are using is binary compatible with the toolset you use to build Boost.
+of ICU you are using is binary compatible with the toolset you use to build Boost.]
 
 [h4 Building via makefiles]