Revision 1897

Modified Data::toString() so it doesn't throw on DataEmpty.
Added setEscriptParamInt and getEscriptParamInt as free functions.
At the moment all they do is allow you to set the param TOO_MANY_LINES.
This is used to determine when printing a Data object will show you the 
points and when it will print a summary.

I've set the default value back to 80 lines.
If you need to see more lines use (in python):

setEscriptParamInt("TOO_MANY_LINES",80000)