Random robot leg assembly does not read by "readtest"

[nickoe]

The iges model from [1], does not save to the output file. It do seem to read some entities, but then readtest gets unhappy.

Tested against ce4cfe6485dac26665dc6d83ff71669a90f416f8.

<snip>
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[INFO] Entity(100) Parameter Data Record for entity at DE 375
    100,9.5,20.,-15.25,20.840990258,-15.25,20.752754683,-14.875;         375
-----
[INFO] Entity(126) Parameter Data Record for entity at DE 377
    126,2,2,1,0,1,0,0.,0.,0.,1.,1.,1.,1.,1.,1.,0.104480445,              377
    0.80952332,0.,0.223171681,0.797761404,0.,0.334047892,                377
    0.783095189,0.,0.,1.,0.,0.,1.;                                       377
-----
[INFO] Entity(126) Parameter Data Record for entity at DE 379
    126,3,3,1,0,1,0,0.,0.,0.,0.,0.000128387680502786,                    379
    0.000128387680502786,0.000128387680502786,0.000128387680502786,      379
    1.,1.,1.,1.,20.375,-15.25,8.747245317,20.375,-15.25,8.79004121,      379
    20.375,-15.245551071,8.833013604,20.375,-15.237266683,8.875,0.,      379
    0.000128387680502786,0.,0.,0.;                                       379
-----
/home/nickoe/libIGES/src/iges/iges_helpers.cpp:82:CheckNormal(): 
 + [INFO] bad vector (cannot be normalized)
/home/nickoe/libIGES/src/entities/entity126.cpp:641:ReadPD(): 
 + [INFO] bad normal
/home/nickoe/libIGES/src/iges/iges.cpp:1497:readPD(): 
 + [INFO] could not read parameter data for Entity[PD:189]
/home/nickoe/libIGES/src/iges/iges.cpp:478:Read(): 
 + [INFO] problems reading file PARAMETER section
 + filename: '/tmp/assieme leg.IGS'
Oops - too bad, better luck next time
 + [INFO] Entities culled: 0
 + [INFO] Entities remaining: 0
/home/nickoe/libIGES/src/iges/iges.cpp:528:Write(): 
 + [INFO ] no entities to save

[1] http://www.3dvia.com/models/010A6437091B2D3F/assieme-leg

[cbernardo]

Some data integrity tests have been relaxed and the model can now be processed.