[libcxx] Unify LIBCXX_<ABI-Name>_INCLUDE_PATHS to be LIBCXX_CXX_ABI_INCLUDE_PATHS

Summary:
Clean up all the different possible CMake options for specifying the ABI include paths into one CMake option named `LIBCXX_CXX_ABI_INCLUDE_PATHS`. 
The documentation has been updated to reflect this change.

For the next week I have added explicit errors if any of the old flags is used. These errors inform users of the change and the new option to use.

Before committing the change I will announce this change on cfe-dev.

Reviewers: danalbert, mclow.lists

Reviewed By: danalbert, mclow.lists

Subscribers: jroelofs, cbergstrom, cfe-commits

Differential Revision: http://reviews.llvm.org/D5039

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@232762 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/www/index.html b/www/index.html
index c608183..c216176 100644
--- a/www/index.html
+++ b/www/index.html
@@ -201,7 +201,7 @@
     <li><code>cd libcxx</code></li>
     <li><code>mkdir build &amp;&amp; cd build</code></li>
     <li><code>cmake -DLIBCXX_CXX_ABI=libcxxabi
-        -DLIBCXX_LIBCXXABI_INCLUDE_PATHS=path/to/libcxxabi/include
+        -DLIBCXX_CXX_ABI_INCLUDE_PATHS=path/to/libcxxabi/include
         -DLIT_EXECUTABLE=path/to/llvm/utils/lit/lit.py .. # Linux may require
         -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++</code></li>
     <li><code>make</code></li>
@@ -373,7 +373,7 @@
      <ul>
        <li><code>CC=clang CXX=clang++ cmake -G "Unix Makefiles"
                 -DLIBCXX_CXX_ABI=libstdc++
-                -DLIBCXX_LIBSUPCXX_INCLUDE_PATHS="/usr/include/c++/4.7/;/usr/include/c++/4.7/x86_64-linux-gnu/"
+                -DLIBCXX_CXX_ABI_INCLUDE_PATHS="/usr/include/c++/4.7/;/usr/include/c++/4.7/x86_64-linux-gnu/"
                 -DCMAKE_BUILD_TYPE=Release
                 -DCMAKE_INSTALL_PREFIX=/usr
                 &lt;libc++-source-dir&gt;</code></li>
@@ -408,7 +408,7 @@
      <ul>
        <li><code>CC=clang CXX=clang++ cmake -G "Unix Makefiles"
                 -DLIBCXX_CXX_ABI=libcxxrt
-                -DLIBCXX_LIBCXXRT_INCLUDE_PATHS="&lt;libcxxrt-source-dir&gt;/src"
+                -DLIBCXX_CXX_ABI_INCLUDE_PATHS="&lt;libcxxrt-source-dir&gt;/src"
                 -DCMAKE_BUILD_TYPE=Release
                 -DCMAKE_INSTALL_PREFIX=/usr
                 &lt;libc++-source-dir&gt;</code></li>
@@ -450,7 +450,7 @@
     <ul>
     <li><code>CC=clang CXX=clang++ cmake
               -DLIBCXX_CXX_ABI=libc++abi
-              -DLIBCXX_LIBCXXABI_INCLUDE_PATHS="/path/to/libcxxabi/include"
+              -DLIBCXX_CXX_ABI_INCLUDE_PATHS="/path/to/libcxxabi/include"
               -DLIBCXX_CXX_ABI_LIBRARY_PATH="/path/to/libcxxabi-build/lib"
               path/to/libcxx</code></li>
     <li><code>make</code></li>