Fix iOS 8 bug with assert fail on infinity CGFloat

iOS 8 produce 'inf' CGFloat instead of CGFLOAT_MAX on some CGPath (some bezier paths). But fails when try to assert this CGFloat as a valid float.
"Assertion failed: (CGFloatIsValid(x) && CGFloatIsValid(y)), function void CGPathMoveToPoint(CGMutablePathRef, const CGAffineTransform *, CGFloat, CGFloat), file Paths/CGPath.cc, line 254."
This fix replace inf with CGFLOAT_MAX and -inf to -CGFLOAT_MAX in the returned coordinates by quartz