PDFBOX-1689: added font manager to handle local fonts

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/branches/1.8@1597849 13f79535-47bb-0310-9956-ffa450edef68
PDFBOX-1689: use the new font manager to search for an external font first

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/branches/1.8@1597852 13f79535-47bb-0310-9956-ffa450edef68