Change Judgment mode of _isBinary
Change Judgment mode of _isBinary

Some ASCII File begin with next code 
will judge ASCII  to Binary
`
solid 中间部分
   facet normal 9.969174e-01 0.000000e+00 -7.845839e-02
      outer loop
         vertex 4.995691e+01 1.566911e+01 2.952479e+00
         vertex 5.000000e+01 1.566911e+01 3.500000e+00
         vertex 5.000000e+01 9.669109e+00 3.500000e+00
      endloop
   endfacet
....
`
sebavan/Babylon.js,RaananW/Babylon.js,sebavan/Babylon.js,RaananW/Babylon.js,sebavan/Babylon.js,BabylonJS/Babylon.js,BabylonJS/Babylon.js,BabylonJS/Babylon.js,RaananW/Babylon.js