PDFBOX-2992: added .gitignore file, as suggested by Ben McCann
PDFBOX-2992: added .gitignore file, as suggested by Ben McCann

git-svn-id: c3ad59981690829a43dc34c293c4e2cd04bcd994@1708705 13f79535-47bb-0310-9956-ffa450edef68

mathieufortin01/pdfbox,mathieufortin01/pdfbox,gavanx/pdflearn,gavanx/pdflearn,joansmith/pdfbox,joansmith/pdfbox