[FIX] Fixing bug in mason_simulator that was triggered by [14581].

git-svn-id: http://svn.seqan.de/seqan/trunk@14600 e6417c60-b987-48fd-844e-b20f0fcc1017
[FIX] Fixing problem with FileStream and its tests.

* The tests did not explicitely give the specialization for the File FileStream.
  This triggered missing tests.
* The itReadEnd member was computed incorrectly for the File FileStream.


git-svn-id: http://svn.seqan.de/seqan/trunk@14601 e6417c60-b987-48fd-844e-b20f0fcc1017