Update cpplint.py to #161:

Update cpplint.py to #161:
- ostream should be treated as a system header
- Expand the MockCallback whitelist entry for gMock.
- Virtual destructor check shouldn't get confused with
  "class EXPORT ClassName {" constructs.
- Don't warn about the length of "$ Id: ... $" lines.
- Better semicolon checks in for() loops.
- Better whitespace comment checks.
Committed: http://code.google.com/p/google-styleguide/source/detail?r=72

[Elliot Glaysher, 2011-09-06 20:59:55]

(There are another 20 revisions to check after this, but I'm so far behind at
this point that I'm splitting this up.)

[Mark Mentovai, 2011-09-07 00:53:23]

LGTM (rubber-stamp)