Merge 76320 - Implementation of an STL compatible allocator for Courgette on ...

Merge 76320 - Implementation of an STL compatible allocator for Courgette on Windows.
This is to better handle low memory situations when applying a differential
patch to a large Chrome setup.

For reading input files, I'm also switching to using memory mapped files
instead of ReadFileToString to reduce the load on the heap.

TEST=courgette.exe should succeed in applying a patch between two
  chrome 10.x archives on an XP machine with 180MB of physical memory and
  no page file.
BUG=72459, 73209
Review URL: http://codereview.chromium.org/6597038

TBR=tommi@chromium.org,kerz@chromium.org

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=76471