Changes to help licenses.py work on Google Chrome officical builds.
Changes to help licenses.py work on Google Chrome officical builds.

Mostly ignores paths for internal tools that get pulled in to official
builds.

Also
  - remove the mingw-w64 comment: confirmed it's only used during build
  - fix the pdfsqueeze include now that DEPS are up-to-date to include
    their 'COPYING' file

BUG= none
TEST= tools\licenses.py scan only complains about xulrunner-sdk on 
official branches (still need to update DEPS there).

Review URL: http://codereview.chromium.org/6269018

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@73910 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser