Bundle pepper PDF plugin on all platforms (issue #1331).
- Add new libpdf.so library on Linux and PDF.plugin app bundle on OS X.
- Move scaled resources from cef.pak into separate cef_100_percent.pak and cef_200_percent.pak files.
- Password-protected PDF files are not currently supported.
- No fallback is provided for PDF files that contain unsupported features.

git-svn-id: http://chromiumembedded.googlecode.com/svn/trunk@1758 5089003a-bbd8-11dd-ad1f-f1f9622dbc98