0029901: Support save to and restore from Stream interface in TObj package

0029901: Support save to and restore from Stream interface in TObj package

Storage and retrieval of a document by means of a stream is distributed to TObj model.
Modified files:
-TObj_Model.hxx, cxx - the virtual methods Load() and SaveAs() obtained a stream as an argument instead of a file name.
-TObj_Application.hxx, cxx - same extension: the virtual methods LoadDocument() and SaveDocument() use a stream to open and save a document.
-TObjDRAW.cxx - draw-commands TObjSave and TObjLoad are extended for -stream parameter, which allows usage of a file input or output stream instead of a file name.

A new test:
- bugs caf bug29901 - it creates a simple TObj-model, saves it on disk using a file stream, loads it by means of a file stream and checks the content.

Modified test:
- bugs caf bug28425 - just improved to proper manipulate a test-file on disk.