Use splitting in ODESOL. Fix DOCs.

The documentation is ```odesol``` and related methods was incorrect, even in V4. It claimed that a piecewise ```chebfun``` was returned with one component per piece.

In reality, both V4 and V5 try to construct a smooth global solution. 

However, there's no way we can how to resolve the VdP problem in the help documentation with a global interpolant. Therefore, we turn splitting on. The VdP example now works wonderfully.