Update ninja to v1.8.2

New binaries for Mac, Linux32, Linux64, Windows.  Also update shell script.
See the bug for how these were built.
The main "new" thing is fix for old cmake.

Bug: 762354, 762407
Change-Id: I4f825e357796e1cb52d2efa041bde46d68cbe152
Reviewed-on: https://chromium-review.googlesource.com/659477Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@google.com>

ninja

@@ -12,7 +12,7 @@ cat <<-EOF
 No prebuilt ninja binary was found for this system.
 Try building your own binary by doing:
   cd ~
-  git clone https://github.com/martine/ninja.git -b v1.8.0
+  git clone https://github.com/martine/ninja.git -b v1.8.2
   cd ninja && ./configure.py --bootstrap
 Then add ~/ninja/ to your PATH.
 EOF