DocumentObject storage including Error and Touch flags, fixes #2156

[abdullahtahiriyo]

Bug including a file to reproduce:
https://www.freecadweb.org/tracker/view.php?id=2156

Just enter a sketch, close and save the file and it will look like this:

   <Objects Count="2">   
        <Object type="Sketcher::SketchObject" name="Sketch" isTouch="0" isError="1" />   
        <Object type="Sketcher::SketchObject" name="Sketch001" isTouch="0" isError="1" />   
    </Objects>   

Close the file, open it again and the error flags will directly appear.

[abdullahtahiriyo]

Close/reopen PR to trigger new Checks, as they failed because of path WB unit tests, having to do with a number of decimal places being different.

[abdullahtahiriyo]

Temporarely hold this PR. There is something odd in a file I created and want to make sure it is right before making you lose your time.

[abdullahtahiriyo]

I have just fixed an issue. We can further proceed.

[wwmayer]

The PR raises a potential problem and a bug.

1. It's possible while saving the document an object used the boolalpha manipulator to write true and false instead of 1 and 0. So, when reading a possible value of true/false isn't handled

2. The method getAttribute() returns a C-string and not a bool. The way it's done here it always will set the touched and error flag.

However, based on this idea I implemented a similar solution which only writes the two status flag when set and used some names that are consistent with the names used in DocumentObjectPy::getState

See 749d666

[wwmayer]

Edit: I have seen your updated PR right now -- too late.

[abdullahtahiriyo]

@wwmayer

Something weird happened this morning that my browser did not update. Never mind. It is all fixed for good :)