MIME4J-316 Parts missing in case of a specific combination of boundaries

The problem can be reproduced by parsing a very specific email structure, where
an inner boundary matches the name of another outer boundary followed by a "-" character.
In the following example, the attached pdf file will be ignored by the parser. 

Merge pull request #2 from bluemind-net/bugfix/BM-18542 (#71)

BM-18542 Fix: check for -- boundary ending

Thanks @tommix000 for the fix.
8 files changed