Log Message:
Update p5-CAM-PDF to 1.55.

Changes from previous:
1.55  22 Jun 2011
      [FIXES]
      Performance enhancement saving large files
      https://rt.cpan.org/Ticket/Display.html?id=69021
      Thanks to David Porter of Audacitas Limited for the patch

1.54  26 Mar 2011
      [FIXES]
      - appendPDF was broken intermittently if appended doc was bigger than main doc
        Thanks to Charlie Katz for a sample PDF
        http://chrisdolan.net/talk/2011/03/26/cam-pdf-fixes-appendpdf-bug/

1.53  25 Mar 2011
      [FIXES]
      - Handle PDF 1.5 case where "endstream" token crosses a \ 
1024-byte boundary
        Thanks to Charlie Katz for a sample PDF
      - Allow whitespace after the 'stream' token for better interoperability
        http://rt.cpan.org/Ticket/Display.html?id=42819
        Credit to Vonne 'Robert' Bannavong
      - Fix broken crunchjpgs.pl, patch submitted by George Greer
      - Tolerate leading zeros on objnums and gennums
        http://www.cpanforum.com/posts/11494