6.2.0 Preview 2 cannot read certain files

[packdat]

Testing the latest version 6.2.0 Preview 2 with my list of test-files, i observed some small issues that prevented the library from reading certain files.

• When reading objects from object-streams, you create instances of PdfObjectStream and Parser to read objects from the stream.
  This can fail when the stream is compressed with the deflate-filter, because you use objectStream.Stream.Value instead of objectStream.Stream.UnfilteredValue. Instances of this here and here.
• There are files out there, where an object is referenced in more than one object-stream.
  This causes an exception here because you try to add an already added object-id to the dictionary.

I attached a ZIP containing 2 documents which could not be read by the library because of the mentioned issues.
Tests were performed with my usual test-case (mentioned for example in #152 )

Issue_Documents.zip

Out of curiosity:
What kind of tests do you run before pushing a new version ?
If you're not doing this already, i highly suggest collection a bunch of files and running a simple import-test against them.
(like the one in #152 )
The issues described here would immediately pop up.