Enable the packed_resources target on Windows.

This target generates the locale .pak files on Windows.  Since nothing
depends on this target, it doesn't build by default (they're not used
yet).

Specific changes:
- Have locale_settings_win.grd generate .pak files.
- Use pymod_do_main to avoid some shell escaping problems (and it's a bit
  faster).
- Rewrite repack_locales.py to work with pymod_do_main.

BUG=92724


Review URL: http://codereview.chromium.org/7648001

git-svn-id: http://src.chromium.org/svn/trunk/src/build@97012 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

gyp_chromium

@@ -19,8 +19,9 @@ chrome_src = os.path.abspath(os.path.join(script_dir, os.pardir))
 sys.path.insert(0, os.path.join(chrome_src, 'tools', 'gyp', 'pylib'))
 import gyp
 
-# Add tools/grit so that pymod_do_main(grit_info ...) can find grit_info.py.
+# Add paths so that pymod_do_main(...) can import files.
 sys.path.insert(1, os.path.join(chrome_src, 'tools', 'grit'))
+sys.path.insert(1, os.path.join(chrome_src, 'chrome', 'tools', 'build'))
 
 
 # On Windows, Psyco shortens warm runs of build/gyp_chromium by about