Fix searching for end of inline (EI) images with ASCII85Decode filters (bug 1077808)

This patch changes searching for the end of inline image streams to rely on the EOD marker for the filters: ASCII85Decode and ASCIIHexDecode.
Merge pull request #5383 from Snuffleupagus/bug-1077808

Fix searching for end of inline (EI) images with ASCII85Decode filters (bug 1077808)