PDFBOX-2048: handle stream that incorrectly claims to have length 0

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/branches/1.8@1590874 13f79535-47bb-0310-9956-ffa450edef68
PDFBOX-2047: A read operation must not alter the pdf; created a test

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/branches/1.8@1590878 13f79535-47bb-0310-9956-ffa450edef68