Add Tim Day's lru_cache_using_std.h to cpp/src/util.

https://bitbucket.org/timday/lru_cache/src/497822a492a8/include/lru_cache_using_std.h

R=rouslan@chromium.org
BUG=

Review URL: https://codereview.appspot.com/101350043
1 file changed
tree: 1be7f9409f9d593196908ea1751622541929ae34
  1. cpp/
  2. externals/
  3. java/
  4. testdata/
  5. .gitmodules
  6. codereview.settings