- update docs to mention the new sysroot support.

docs/buildroot.html

@@ -362,7 +362,7 @@ $ make HOSTCXX=g++-4.3-HEAD HOSTCC=gcc-4.3-HEAD
       default). This is where the cross-compilation toolchain will be
       installed. If you want to use the same cross-compilation toolchain for
       other purposes, such as compiling third-party applications, you can add
-      <code>build_ARCH/staging_dir/bin</code> to your PATH, and then use
+      <code>build_ARCH/staging_dir/usr/bin</code> to your PATH, and then use
       <code>arch-linux-gcc</code> to compile your application. In order to
       setup this staging directory, it first removes it, and then it creates
       various subdirectories and symlinks inside it.</li>
@@ -390,7 +390,7 @@ $ make HOSTCXX=g++-4.3-HEAD HOSTCC=gcc-4.3-HEAD
 
     <p>The toolchain generated by Buildroot by default is located in
     <code>build_ARCH/staging_dir/</code>. The simplest way to use it
-    is to add <code>build_ARCH/staging_dir/bin/</code> to your PATH
+    is to add <code>build_ARCH/staging_dir/usr/bin/</code> to your PATH
     environnement variable, and then to use
     <code>arch-linux-gcc</code>, <code>arch-linux-objdump</code>,
     <code>arch-linux-ld</code>, etc.</p>
@@ -401,7 +401,7 @@ $ make HOSTCXX=g++-4.3-HEAD HOSTCC=gcc-4.3-HEAD
     <code>~/buildroot/</code>) :</p>
 
 <pre>
-export PATH=&quot;$PATH:~/buildroot/build_mips/staging_dir/bin/&quot;
+export PATH=&quot;$PATH:~/buildroot/build_mips/staging_dir/usr/bin/&quot;
 </pre>
 
     <p>Then you can simply do :</p>
@@ -410,12 +410,15 @@ export PATH=&quot;$PATH:~/buildroot/build_mips/staging_dir/bin/&quot;
 mips-linux-gcc -o foo foo.c
 </pre>
 
-    <p><b>Important</b> : do not try to move the toolchain to an other
+    <p><b>Important</b> : do not try to move a gcc-3.x toolchain to an other
     directory, it won't work. There are some hard-coded paths in the
     <i>gcc</i> configuration. If the default toolchain directory
     doesn't suit your needs, please refer to the <a
     href="#toolchain_standalone">Using the uClibc toolchain outside of
     buildroot</a> section.</p>
+    <p>If you are using a current gcc-4.x, then use --sysroot and -isysroot
+    since these toolchains have fully functional sysroot support. No
+    hardcoded paths do exist in these configurations.</p>
 
     <h2><a name="toolchain_standalone" id="toolchain_standalone"></a>Using the
     uClibc toolchain outside of buildroot</h2>
@@ -424,10 +427,11 @@ mips-linux-gcc -o foo foo.c
     <code>build_ARCH/staging_dir/</code>. But sometimes, it may be useful to
     install it somewhere else, so that it can be used to compile other programs
     or by other users. Moving the <code>build_ARCH/staging_dir/</code>
-    directory elsewhere is <b>not possible</b>, because they are some hardcoded
-    paths in the toolchain configuration.</p>
+    directory elsewhere is <b>not possible if using gcc-3.x</b>, because they are some hardcoded
+    paths in the toolchain configuration. This works, thanks to sysroot support, with current,
+    stable gcc-4.x toolchains, of course.</p>
 
-    <p>If you want to use the generated toolchain for other purposes,
+    <p>If you want to use the generated gcc-3.x toolchain for other purposes,
     you can configure Buildroot to generate it elsewhere using the
     option of the configuration tool : <code>Build options -&gt;
     Toolchain and header file location</code>, which defaults to